As technology continues to shrink, more features are being packed into these small mobile devices, making navigation and ease-of-use more important. This week, I tested the Motorola ROKR E8, which costs $199 with a two-year T-Mobile service agreement and makes a real attempt to be more user-friendly. The device, which comes out on July 7, isn’t much bigger than a typical cellphone but its standout feature is its keyboard, which dynamically changes to accommodate whatever you’re doing at the time, revealing only buttons that would be of use to that particular function.

The secret sauce on the ROKR E8 is its keyboard, which changes when it’s used as a phone, music device and camera.

The surface of the ROKR E8 has no physical keys at all. In its off or resting state, in fact, it’s just a black surface with rows of tiny, unlabeled bumps. But this surface is actually divided into two: The top half works like a typical cellphone display while the bottom half projects virtual keys onto its surface and uses the rows of bumps to give these keys a physical presence.

When making a call or sending a text message, the ROKR’s surface displays a regular phone keypad. But as soon as a music shortcut button is pressed, the surface morphs into five buttons for music navigation: play/pause, seek forward, seek backward, shuffle and repeat. Pressing another shortcut button to start the ROKR’s camera mode shows four buttons for zooming in or out, switching to playback mode or changing to video. Motorola (MOT) calls this its ModeShift technology. Though the lower half of the ROKR can be considered a touch device, objects can’t be manipulated with gestures like pinching or dragging as with the Apple (AAPL) iPhone’s multitouch screen.

Overall, I found that the ROKR E8’s dynamic keyboard gave me a real advantage in figuring out how to use the multi-functionality of the phone. Its changing keyboard eliminated a lot of guesswork and time that I may have spent hunting through menus for a command. And true to its name, the ROKR (pronounced “rocker”) is focused on its music phone functionality with an FM radio, a neatly organized music menu and a speaker that has convincingly simulated surround-sound effects.

But this ROKR didn’t always jam out in perfect pitch. A touch-sensitive semicircle in the center is meant to make scrolling through long lists easier — much like Apple Inc.’s iPod wheel. But because this tool on the ROKR isn’t a full circle, scrolling felt unsatisfying. You also can’t buy songs with the ROKR, or even mark songs for purchasing later on a PC.

And while the morphing buttons look futuristic and hip, I experienced a few instances when the phone was slow to react after I touched a button, as when I touched the seek forward button while listening to music or when I chose to open an MMS message I sent to a friend.

Twenty-two tiny bumps dot half of the ROKR’s surface, and the surface below each bump vibrates when it’s touched to provide sensory feedback. Nothing is ever physically pressed down, though the vibration response leads you to think otherwise.

A smart switch on the side can be held down to turn it on or off, or switched into the upward position to lock the device, preventing accidental calls or battery drain.

The ROKR E8 runs on T-Mobile’s (DT) GPRS/EDGE connection, which felt sluggish at times. And not even the dynamic keyboard on this device could help make email or instant messaging easier.

It has a two-megapixel still camera with an 8x digital zoom that can change into video-camera mode in one step. Two gigabytes of memory are built into the ROKR, and more memory can be added via a microSD card slot, which is hidden beneath a back panel. A one-gigabyte microSD card comes with the ROKR. Without this card, the internal memory will hold about 1,500 songs.

With help from a USB cord and Windows (MSFT) Media Player 11, I transferred over 200 MP3s onto my ROKR. Album art that transferred with my songs appeared on-screen as songs played, and the speaker gave off a powerful sound. Built-in stereo Bluetooth can send tunes to Bluetooth-enabled stereo speakers, and it took me just a few seconds to pair my ROKR with Motorola’s EQ5 speakers.

A preloaded program by Shazam lets users hold the ROKR up to any speaker playing a song, and in 30 seconds, identifies the track title, artist, and album art. I held the ROKR up to my alarm clock radio and it worked perfectly. But once these songs are recognized, the track data can’t be used to buy the song or even to transfer a request to buy that song to a PC for buying online at another time.

The ROKR’s FM radio will work only if its included stereo headset is plugged in because the headset has the radio antenna. But once the headset is plugged in, the radio will play via the ROKR’s speaker.

The ROKR E8 has an audio technology called Crystal Talk, which Motorola says allows your phone to perform better in loud environments. Even if the person on the other end of your phone is in a noisy place, the company says Crystal Talk will raise the volume to improve the call. I tested this by speaking to someone on the ROKR while turning a hairdryer on beside the phone. I then used a regular Razr cellphone. The person on the other end said that the ROKR sounded slightly, but noticeably, better.

Motorola’s ROKR E8 is a head-turning phone with many built-in advances that give it a smarter interface. One might wonder what other ModeShift functions the company will integrate into its devices in the future, such as a full QWERTY keyboard. The overall idea of a dynamic keyboard is a step ahead for small devices. It forces the phone to work more intuitively and improves navigation while looking stylishly sleek at the same time.

Edited by Walter S. Mossberg.

Write to Katherine Boehret at mossbergsolution@wsj.com

Last year, when Microsoft Corp. introduced its Zune music player to take on Apple’s iPod juggernaut, the software giant struck out. While the Zune had a good user interface and a larger screen than the iPod, it was bigger and boxier, with clumsier controls, weaker battery life and more complex software. Its companion online music store had a much smaller catalog, a more complicated purchase process and no videos for sale. And the Zune’s most innovative feature, built-in Wi-Fi networking, was nearly useless and added little value to the players, which sold so poorly that Apple barely noticed.

The Zune Pad adds touch functionality for improved navigation.

But Microsoft is nothing if not persistent, and this week, the company is back with a second, improved round of Zunes. The chunky, older 30-gigabyte model remains in the lineup, but it’s joined by a slimmed-down full-size Zune that holds 80 gigabytes, and by a much smaller model that holds four or eight gigabytes. Prices range from $150 to $250. The 80-gigabyte Zune is available only in black, and the others come in red, green, black and pink.

We’ve been testing these new Zunes and find them to be notably better than last year’s entry. They are smaller, lighter and more attractive, and they include three big improvements. First is a new controller, called a Zune Pad, that combines buttons with a touch pad for scrolling. Second is a completely overhauled, simpler PC-software program and online store, the Zune Marketplace. Third is expanded usability of the built-in Wi-Fi, which allows you to synchronize your Zune and your PC without plugging in a cable and makes sharing songs between Zunes — its only function last year — slightly better.

Zune’s Marketplace is visually attractive.

Unfortunately for Microsoft, Apple hasn’t been standing still, either. It now has its own large-screen, wireless model, the iPod Touch, with a radical “multi-touch” interface like the iPhone’s. The screen on the Touch is larger than the one on the bigger Zunes and is much sharper. Its Wi-Fi allows you to browse the Web, watch YouTube videos and even buy music without a PC — none of which is possible on a Zune — though the Touch is $50 more and holds much less content than the new full-size Zune.

Microsoft’s new Zunes are directly aimed at the iPod Classic, Apple’s full-size, high-capacity model, and the iPod nano, its compact version. But, here again, Apple has been on the move. The 80-gigabyte Classic, which costs the same as the 80-gigabyte Zune, is slimmer than the Zune and has a flashy new interface, if a smaller screen. And the eight-gigabyte nano, which costs the same as the eight-gigabyte Zune, now plays videos and is much smaller — yet has a larger screen. Neither of these iPods includes Wi-Fi.

In addition, Apple has spiffed up its iTunes software, adding various features, including the addictive Cover Flow, which allows you to flip through all your albums with just a flick of the mouse. Cover Flow also shows up on the nano, the Classic and the Touch. Even the new Zune PC software has no interface as compelling.

And Apple still trounces Microsoft in the selection of media it sells. The iTunes store offers more than six million songs, about double what the Zune Marketplace offers, and dwarfs Microsoft’s selection of Podcasts and music videos, as well. Plus, Zune Marketplace still doesn’t sell any TV shows, movies or audiobooks, while iTunes does.

Radio Feature

Overall, we still don’t think the Zune line beats the iPods and iTunes. However, one of the Zunes, the full-size Zune 80, could give the iPod some competition, especially among new digital-player buyers who aren’t invested in the iTunes ecosystem. For the same price, it offers a significantly larger screen (albeit with the same resolution), wireless syncing and sharing, and a built-in FM radio — an existing Zune feature that the iPod lacks.

We tested the $249.99 80-gigabyte Zune 80 against Apple’s iPod Classic with the same capacity and price and then did the same for the $199.99 eight-gigabyte Zune 8 compared with the iPod nano equivalent.

We didn’t get a chance to test the battery life on the new Zune models or that of the iPod Classic and nano. But Microsoft concedes that unless you turn off Wi-Fi — one of the Zune’s key advantages — its claimed battery life is lower than Apple’s claims. Microsoft estimates as many as 19 and 24 hours of music playback with Wi-Fi on for the eight- and 80-gigabyte, respectfully. Apple claims as many as 24 hours and 30 hours, respectively, on the competitive models, which lack Wi-Fi. In the past, Apple has generally understated its battery claims, while last year, Microsoft overstated its claims.

Easier Navigating

On both Zunes, the front hosts just three buttons: the Zune Pad, a back button and a Play/Pause button. Its menus are divided into Music, Videos, Pictures, Social, Radio, Podcasts and Settings; navigating through this menu list and hundreds of songs is made easier with the Zune Pad’s touch functions. To zip through a list, we flicked a finger up or down. The top, bottom, right and left sides each work as individual buttons, as does the center of the Zune Pad.

The user interface is mainly unchanged from last year and still works very well, requiring an economical number of steps for each action.

Zune’s black, red and green colors are fine, but rather masculine — the latter reminded us of camouflage. But the pink was a glaring shade more appropriate for My Little Pony; it looks like an afterthought.

We initiated wireless syncs with the Zune software program, plugging the player into our PC the first time but leaving it disconnected each time after that. Wireless syncing took a little longer than with a cord and must be initiated by the user from within the player’s settings. One frustration: Presumably to save battery life, the Zune disconnects from the network periodically and then must reconnect the next time you want to use the Wi-Fi. Also, the Zune can’t wirelessly sync if you’re at a public hot spot that requires you to log in or pay.

Intelligent Syncing

This year’s Zunes also introduce a concept Microsoft intends to build on: intelligent, or automated, syncing. If you have your Zune set to sync only some of your music, not all, and drag an artist’s name onto the Zune icon in the PC software, the software will thereafter automatically sync every song you add to the PC from that artist. Microsoft believes many people would welcome such automation.

The Zune’s FM radio is well-designed and easy to use. Using the Zune Pad to flick left or right along the station grid, our Zunes detected numerous static-free stations, and we marked certain stations as presets by holding down the center button. Each radio’s digital data appeared on-screen, including the artist and song title.

We shared songs between our Zunes, beaming tracks from the 80-gigabyte to the eight-gigabyte and vice versa. A wirelessly shared song can be played by the recipient three times whenever they choose. Microsoft has removed the three-day time limit that applied last year. A minute of playing time, or half the duration of a song (whatever comes first) constitutes one play. At first, it took our Zunes a couple tries to recognize one another, even though they were both set to share music. And we noted that invitations to accept shared music don’t include any information about the music, so you could get stuck downloading an annoying tune or one you already own.

Photo Finish

Photos and videos looked great on the Zunes — about as good as they do on the comparable iPod nanos and better than on the iPod Classic because that iPod model’s screen is much smaller than its Zune counterpart’s. However, album art, which is often lower-resolution than normal photos, looked grainier on the big Zune than on the big iPod. And none of the Zunes came close to the stunning photo and video quality offered on the iPod Touch and the iPhone.

We didn’t get to test Zune’s a la carte point system for buying and downloading tracks because it wasn’t up and running yet. Neither were music-video downloads. We each had Zune Pass accounts, which work like subscriptions. If the Zune account stops, all content acquired during the user’s subscription is lost.

Album Focus

Navigating through Zune’s software can be a tad confusing. Four categories at the top left of your PC’s screen are meant to help: Collection, Device, Marketplace and Social. Collection shows your downloaded or owned content and focuses a bit too much on albums, which are becoming less significant with the ever-growing popularity of digital music. One example of this is the Collection’s default center panel shows album art sorted by date added.

Zune Marketplace’s artist pages really shine. Upon selecting a band or artist, a rich, full-screen background image of that group or person appears on the page with lists of songs floating atop the image. Various still photos of each artist are included; we found 10 for Mary Chapin Carpenter and 15 for Nelly Furtado.

A full-screen artist page for Avril Lavigne on Zune Marketplace

After listening to a Yo-Yo Ma album in her music collection, Katie wanted to download additional performances of the famous cellist from the Zune Marketplace online store. But, unlike iTunes, Zune’s software program doesn’t offer a way to link directly from your Collection to Marketplace for buying more of a certain artist or another song from an album you already own.

Another navigational hiccup in Zune’s Marketplace is its inability to bookmark searches. If, after searching in Zune’s online store to buy and download more Yo-Yo Ma, Katie looked in her Collection to see which piece she played last or liked most, then returned to the online store, her Marketplace store search would be lost and she’d need to start over. The iTunes store bookmarks your place during searches, allowing you to navigate through any other part of iTunes before returning to the idle search.

Zune tries to compensate for this glitch by identifying songs in the online store that you already own — either bought through Zune Marketplace or from other sources — with an “In Collection” label so you don’t accidentally buy content you already own. Likewise, if a song in your Collection is already synched to be on the player, a tiny Zune icon appears beside that song title.

Unlike iTunes, Zune software can’t create smart playlists. And it only offers two views, Browse and List, versus three in iTunes: Cover Flow, lists, and lists with album art.

Microsoft has greatly improved the Zune hardware and software this time. But it seems to be competing with Apple’s last efforts, not its newest ones.

• Email mossbergsolution@wsj.com

How do you dislodge Apple’s mighty iPod music player, and its popular iTunes music service, from their total dominance in the digital-music market? Numerous hardware companies and music services — most backed by Apple’s historic rival, Microsoft — have tried, and failed, with all sorts of approaches.

Some contenders were cheaper. Others had built-in features the iPod lacked, like FM radios. Some had more capacity, or greater battery life. Others relied on monthly subscriptions instead of per-song fees. But the public has mainly yawned, and none of these approaches has gained any traction.

Today, a small New York City company called MusicGremlin Inc. is rolling out a fresh approach to denting the iPod hegemony: the wireless music player. Its new $299 Gremlin portable player has built-in Wi-Fi wireless networking, so it can download songs from an accompanying subscription service directly, without requiring the use of a personal computer.

Not only that, but Gremlin users can wirelessly exchange entire songs right from their players, legally, as long as both the sender and receiver are subscribers to the MusicGremlin Direct service, which costs $14.99 a month. This process, called “beaming,” allows you to share songs with your Gremlin-toting pals, no matter where they are, without ever using a computer or a CD burner. You can even peer into other users’ Gremlins to see what they’re playing and what they’ve downloaded, and pluck any song you like from their devices, if they give you permission.

The Gremlin is available today at Amazon.com, and the company’s own Web site, musicgremlin.com. While it doesn’t require a computer, the Gremlin can synchronize with a PC, but this only works with Windows machines. Its Web site requires Microsoft’s Internet Explorer browser and Windows Media Player for full functionality. The subscription service, which is optional, is free for the first month and offers unlimited downloads from a catalog of two million songs, about the same size as Apple Computer’s catalog.

We’ve been testing the Gremlin player and the MusicGremlin service, and we like them. The experience of downloading new music from the palm of your hand and sharing it legally with others is refreshing and fun, and can’t be done on our trusty iPods. Plus, MusicGremlin is one of the few iPod competitors we’ve encountered that shares Apple’s strong dedication to a smooth, end-to-end experience, where the hardware, software and online service work seamlessly.

However, this first version of the Gremlin has some major rough spots, in its user interface and in its wireless behavior, that detract from the experience and can get downright annoying. The company promises to fix these, but some other limitations can’t be repaired as easily. For instance, the magic doesn’t work if you aren’t in range of a Wi-Fi network you can use. And limitations imposed on MusicGremlin by the record labels mean that you can’t share certain kinds of songs, including legally obtained MP3 files that you transfer to the Gremlin from your computer.

Also, for $299, the Gremlin holds far less music than the $299 base model of the full-size iPod — just eight gigabytes, or 2,000 songs, versus 30 gigabytes, or 7,500 songs, for the $299 iPod.

The Gremlin player is a rather plain, black, chunky-looking device with none of the visual sex appeal of the iPod. It’s the same width as the base $299 model of the full-size iPod, but slightly shorter and thicker, at 0.76 inches, versus 0.43 inches for the iPod. At four ounces, it’s lighter than the iPod (which weighs 4.8 ounces).

The Gremlin’s color screen is smaller than the iPod’s — two inches, versus Apple’s 2.5 inches. And, instead of Apple’s excellent scroll wheel, the Gremlin uses a clumsier five-way navigation pad, like the ones on some cellphones. The Gremlin’s volume and playback controls are on its side. Battery life is 10 hours, versus 14 hours for the similar-size iPod.

Unlike the iPod, the Gremlin can’t display photos or videos. It can technically play back podcasts or audiobooks, but no podcasts and only a few audiobooks are yet available on the MusicGremlin service. It does include an FM radio, which the iPod lacks.

In our tests, the wireless features worked well — when we were able to get wireless connectivity. We could pick from the service’s huge catalog and download songs at will. The device shows you how many songs are queued up for downloading and reports on its progress in fetching them. If you lose the Wi-Fi connection, the process pauses and resumes later when you’re connected again.

We were also able to send and receive songs via beaming. We saw a list of other users and could easily send them songs and receive beams, giving permission each time.

But the Gremlin often told us it couldn’t find a wireless network, even when we were just a few feet from a Wi-Fi base station that laptops in the room located easily. And, in order to save battery power, the Wi-Fi feature shuts itself off frequently. It can be slow to come back and sometimes doesn’t come back at all.

On one occasion, when we were sitting next to each other with our test Gremlins, the devices couldn’t see each other, because the Wi-Fi on one or the other device had turned off automatically and wasn’t coming back up.

A last-minute software upgrade yesterday improved some of this wireless behavior, but the company acknowledges that more work is needed. (The device can be quickly upgraded by the company with bug fixes and new features, over the wireless network.)

The Gremlin won’t work with some commercial Wi-Fi hot spots, which require a Web browser to connect. But it comes with the built-in ability to connect to T-Mobile’s large network of Wi-Fi hot spots, if you have a T-Mobile account and enter your account information into the Gremlin.

The user interface is much clumsier than an iPod’s. This is partly because there are more functions, like downloading, and the community-sharing capabilities. But some things aren’t well thought out. For instance, it’s not obvious how you get the song-playing display, which shows the album cover, to stay on-screen for more than a few seconds.

To pick a song out of a list, you have to laboriously enter letters of the alphabet using the down arrow, and many functions require lots of arrow clicks and navigating fly-out submenus. Again, the company promises to improve some of this navigation.

We easily synchronized music from our computers to the Gremlin, using a Windows PC and Windows Media Player. You can also view the Gremlin as an added disk on your Windows PC and just drag and drop files between the Gremlin and your hard disk. Only the latter method allows you to copy subscription songs from the Gremlin to the PC.

One really cool feature is the MusicGremlin Web site, which not only allows downloading of songs to either a Gremlin player or a PC, but automatically displays a list of all the subscription songs on your Gremlin.

Both the Web site, and the Gremlin itself, offer you the option of purchasing songs outright, for 99 cents each, just as on Apple’s iTunes service. Unlike the subscription downloads, these songs don’t expire if you end your subscription.

In fact, you could buy a Gremlin and decline to join the MusicGremlin Direct subscription service, just filling your Gremlin with purchased tunes or songs transferred from your PC. But you’d lose the community feature of the Gremlin, because only subscription songs can be shared.

Despite its drawbacks, the MusicGremlin player and service are a great idea done pretty well. There’s nothing else like them in the marketplace, and they represent a fresh approach to challenging the iPod. For some people, a system that cuts out the need for a PC and allows legal sharing of songs may just be the perfect iPod alternative. But the company will have to file off the Gremlin’s rough edges if it’s to succeed.

• Email: MossbergSolution@wsj.com

There are scores of products that attempt to solve this problem, ranging from simple in-car iPod mounting kits to more elaborate gadgets that recharge the iPod and connect it to a car’s audio system via a cassette adapter, or an FM transmitter that routes the music through a vacant radio-station setting. Some of these devices also can use a cable that plugs the iPod directly into a built-in audio input jack, if your car is in the small minority of models that have such a jack, or if you have had an installer add one.

he $199 Drive + Play by Harman Kardon. For more information: www.driveandplay.com.

However, almost all of these options still force you to rely on the iPod itself for navigating your song list, requiring you to look down at its screen and reach for its scroll wheel while you should be focusing on driving. The principal options to avoid this distraction are expensive: factory-designed iPod connector kits that transfer the iPod display to your dashboard’s screens, and in some cases, enable you to control the iPod with buttons built into the steering wheel. But these are only available in a limited number of mostly high-end cars. There are a few add-on kits with auxiliary screens and controls, but these are costly, and require professional installation.

This week, my assistant Katie Boehret and I tested a new, modestly priced, supposedly simple, iPod auto accessory that just might ease the iPod distraction problem. It is the $199 Drive + Play by Harman Kardon, a division of Harman International Industries Inc.

Unlike most of the iPod automotive accessories, this product uses its own screen and controller. These enable you to put your iPod away in the glove compartment, while still seeing the player’s menus and song info on a larger screen that sticks onto your dashboard, in your line of sight. The separate controller, sort of a gearshift for music, can be placed anywhere that is comfortable and safe. It is a small, circular unit with a movable outer ring that emulates the iPod click wheel using Play/Pause, Menu, and Seek buttons in the same positions as the iPod’s click wheel buttons.

In our tests, the Drive + Play worked without a hitch and freed us from relying on the iPod’s display and buttons. Still, the unit has a rat’s nest of cables, and installing it while hiding these cords would be tough, especially if you put the screen and controller in the least distracting locations, right near the driver. We suspect this task is beyond the skill of most people, so we believe the gadget would require hiring an installer, at considerable extra cost.

Also, while the Drive + Play eases the eyes-on-the-road problem, it doesn’t really help with the hands-on-the-wheel dilemma. You still must remove a hand from the wheel to fiddle with song selections, just as if you were controlling the iPod directly.

The Drive + Play consists of three basic parts: the screen, the controller and the “brain” — a gray box to which those two attach using rather ugly black cords. Two more cords also plug into the brain, one that attaches to the base of any dockable iPod and another that connects to your car’s cigarette lighter for power.

There are three ways to operate your Drive + Play, and Katie and I tested two of them by driving around downtown Washington, D.C., and its Maryland and Virginia suburbs, in my car. Setting up the brain and wire-attached devices was simple, but once the four wires were attached to the screen, controller, iPod connector and power outlet, the brain resembled a bomb. The snaky black wires running from it weren’t easy to hide, either, and even if you hid the brain and iPod in your glove compartment, you still would have at least three more wires to deal with.

The display screen for the Drive + Play can be mounted on the dashboard, while the gadget’s controller can be placed within comfortable reach of the driver.

The display screen and controller come with adhesive so you can stick them wherever you want to in your car, but keep in mind that you will have to cleverly disguise their corresponding wires, too. We set up the screen and controller, plugged in the power adapter and attached my iPod mini to the iPod connector.

The cheapest and easiest way to use your Drive + Play is with its built-in FM transmitter. We did this by tuning my car’s FM radio to 88.1, selecting a song using the controller and pressing the “Play” button, located in the lower center of the controller’s circular face, right where the same button is on an iPod.

The wheel on the Drive + Play’s controller is a little tough to get used to, but it soon became more familiar. Instead of turning around completely, the controller’s ring is set on springs to turn just a little right or left before springing back into its resting position. A short turn scrolls up or down through your display’s menus, holding the ring a little longer fast-forwards or rewinds through an individual song and holding it even longer skips to the next or previous song. A glowing blue circle surrounds the large, center “select” button.

The Drive + Play backlit display legibly shows menus that mirror those on the iPod — minus the “Shuffle Songs” shortcut in the main menu. Shuffle and other options, including a font-enlarging alternative, can be adjusted within a “Settings” menu. Each song’s title, artist and duration showed on our display, and the title can be set to scroll across your screen, like on the iPod.

We listened to individual songs, as well as a few playlists on my iPod mini. Using the controller to navigate tunes was simple because it worked like an iPod.

The built-in FM transmitter, while easy to set up, was plagued by static, and we found that we had to move the iPod mini around more than once to get better reception. This would make driving even more dangerous.

For better results without tapping into your car’s audio system, you can buy a wired FM transmitter adapter from Harman Kardon for $29, though we didn’t test this method.

The third and most expensive method unsurprisingly returned the best results in our tests. This involved using a preinstalled auxiliary jack in my car’s glove compartment that connected the brain directly to my car’s audio system. Very few cars come with such a jack. Harman Kardon estimates that this basic installation would cost about $70.

We turned off the FM transmitter and attached the auxiliary cable to a connector on the brain, adding yet another cord to the four already in place. A few seconds later, static-free music came through my car’s audio system.

The Drive + Play works, but it doesn’t eliminate all driver distraction. And those wires are a real challenge.

With reporting by Katherine Boehret

• Email me at mossberg@wsj.com

Of course, if you stock numerous extra batteries for each device, and keep them charged fastidiously, you might ride out a long power outage. But that takes a fat wallet and an iron will. You could use a car charger to keep these gadgets going in a power outage, but during Katrina many people couldn’t get gasoline to power their cars. You could recharge your gadgets from a home generator, but few people own them or stockpile the fuel they consume.

The Multi-Purpose Radio FR300 by Eton

So this week, my assistant Katie Boehret and I tested gadgets that are specifically designed to work in emergency situations. We tested two radios that use cranks to recharge their batteries, including one with a built-in cellphone charger. We also took a look at disposable chargers for cellphones, smart phones and even iPod music players.

Obviously these products won’t help you stay connected should the communications infrastructure itself go down, as happened during Katrina. If the cellphone towers, Internet providers, and TV and radio stations are knocked offline, even a well-charged laptop, phone or radio might be useless. But it’s best to have your end of the system ready if some of these networks do remain operational, or come back on line during the crisis.

The crank radios were pretty easy to set up and use, which is a relief for anyone who might buy them and not learn how to use them until actually necessary. We found the $50 Multi-Purpose Radio FR300 by Eton Corp. at Hammacher Schlemmer (www.hammacher.com) and liked its multifaceted functionality, which includes picking up the audio signal from TV stations.

Freeplay Eyemax Weather Band Radio from Innovative Technologies Distribution Inc. Price: $69.99. For info: www.windupradio.com

This sturdy-looking, square radio has a carrying handle on top and comes with a case. Its front displays a speaker, small flashlight, and tuning display for five settings: AM, FM, the TV1 and TV2 television audio bands, and a “WX” band for the government’s weather channels. Katie used a slide bar just below that display to choose which she wanted to hear. She turned the tuning knob to hear a specific radio station; a smaller knob built into the larger knob allows for more precise tuning. There is a collapsible antenna.

To generate power for the FR300, we simply folded a plastic crank out from the radio’s side, and turned it for a little while, evoking a loud whirring sound. Eton says that two minutes of cranking should suffice for an hour of radio play time, but we got 35 minutes out of a 30-second crank, which is even better than that estimate.

National Oceanic and Atmospheric Administration broadcasts can be tuned in on the FR300 by setting the slide bar to the WX setting. A separate tuning knob lets you turn to whichever is the strongest of the seven NOAA channels. You can set another separate knob on “Alert” so as to hear whenever the NOAA announces emergency weather news in your area. A siren is also built into this radio.

A small cellphone-charging piece plugs into the back of the FR300, and five included adapters permit charging of certain Samsung, Motorola, Nokia, Siemens and Sony Ericsson phones. Katie easily plugged her Samsung cellphone into the adapter and had it charging after a few cranks.

The $70 Freeplay Eyemax Weather Band Radio from Innovative Technologies Distribution Inc. (www.windupradio.com) was similar to the FR300, but it lacked a few features. This radio has its crank, speaker and tuning display all lined up on the front, with a tiny flashlight at one end and an antenna at the other.

iRecharge for iPod mini by Compact Power Systems Inc. Price: sold in $79.99 Value Pack. For info: www.cellboost.com

A solar panel on its top can be used to operate the radio in direct sunlight, which might be a nice feature if you’re not up for repeated hand-cranking. The Freeplay also comes with an AC adapter, unlike the FR300. But the FR300 can run on three AA batteries, which might be more useful during an evacuation; the Freeplay had no option for disposable batteries.

While the Freeplay Eyemax is also advertised to receive seven NOAA weather-band channels, its weather-tuning display is confusingly represented on the same display as AM/FM tuning. We liked the FR300’s separate weather-channel knob better because it allowed us to set one weather station and not have to change it after listening to the radio.

The Freeplay’s estimated crank/run time was more accurate — as the company said, 30 seconds of cranking enabled the battery to work for 35 minutes, the same as the FR300.

Katie and I also re-tested a product we have reviewed in the past — Cellboost by Compact Power Systems Inc. These are tiny disposable cellphone chargers that can give your phone 60 minutes of usage time or 60 hours of standby time. But this month, the company introduced the same devices for smartphones, which are cellphones designed for email and Web browsing. Other new Cellboost models power portable game stations, camcorders and even iPod music players — though these aren’t necessarily emergency lifelines.

Cellboost for Treo smartphones by Compact Power Systems Inc. Price: $7.99. For info: www.cellboost.com

I use the Treo 650 smart phone every day, for email and phone calls, so I tested the $8 Treo Cellboost, which promises 60 minutes of talk time. As soon as I attached the Cellboost and flipped its on/off switch, it worked like I had plugged my smartphone into its wall charger. Katie tried the $8 BlackBerry charger and the $10 iPod mini charger with the same simple results. The Cellboosts for iPod and iPod mini each afford eight hours of play time.

Compact Power Systems also introduced a product called the iRecharge, a rechargeable portable battery that fits snugly around your iPod, iPod mini or iPod shuffle giving the iPod and iPod mini 12 hours of extra play time and the iPod shuffle 40 extra hours. It has an on/off switch, so you can charge your iPod as needed, as well as a charge-level indicator that glows to tell you how much juice is left.

Katie used the iRecharge with her mini, and it worked easily. The iRecharge for iPod and iPod mini is sold for $80 in a Value Pack with a disposable iPod Cellboost, belt clip and a leather carrying case. The iPod shuffle’s iRecharge Value Pack costs $40.

We highly recommend getting a couple of Cellboosts to keep in your briefcase, purse or glove compartment; each charger remains usable for up to two years. And we recommend a crank radio as well. But, while Cellboosts are an inexpensive solution for recharging your gadgets, crank radios are more of an investment. Be sure to look for one with as many power sources as possible — such as a slot for disposable batteries and AC adapter — and make sure it includes a good flashlight.

Then, pray you don’t have to use any of these things.

With reporting by Katherine Boehret

• Email me at mossberg@wsj.com