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

Polaroid’s $150 PoGo is an inkless printer that churns out 2×3-inch photos sent to it via Bluetooth-enabled devices or from plugged-in digital cameras.

Just this year, Polaroid Corp. said it would cease production of its “magical” cameras. But this week, I had the chance to test the company’s latest attempt at relevance in our digital world: the $150 Polaroid PoGo (thenewinstant.com). The PoGo, which stands for Polaroid-on-the-Go, is an inkless printer that churns out 2×3-inch photos sent to it via Bluetooth devices like cellphones or from plugged-in digital cameras. It uses technology created by ZINK (Zero Ink) Imaging Inc. to activate paper-embedded dye crystals, creating a new kind of photo magic. The PoGo will be in stores on July 6.

Cool Factor

This device’s ZINK Technology gives it a cool factor that will leave friends scratching their heads over how such a small device can print without ink (technical details about the 100 billion heat-activated dye crystals on each sheet of paper can be found at zink.com/technology). Photos that I printed from a 10-megapixel digital camera looked sharp and colorful. And some people may use this Polaroid gadget as a solution for freeing images that would otherwise likely remain stuck in a mobile device’s memory.

But four major problems with the PoGo make it a no-go: It isn’t quite small and light enough to be truly portable; its battery life is poor; its prints are half the size of normal photos; and image quality when printing from mobile devices is unimpressive — though this can be attributed to the low-resolution images taken with and stored on these devices rather than the printer itself. For roughly the same price, you could buy a photo printer that produces better quality 4×6-inch or larger prints.

The PoGo works only with ZINK Photo Paper, which costs between 30 cents and 40 cents a page, depending on whether you buy a 10-sheet pack for $3.99 or a 30-sheet pack for $9.99. (Later this year, a 100-sheet pack of ZINK photo paper will be available for $29.99.) The PoGo comes with 10 pieces of this paper, which is coated with a waterproof, tear-proof, smudge-proof, semi-gloss finish. You can peel the backs of these 2×3 prints to stick them to things, though not in the same way Post-its can be stuck and removed (they leave a gooey film — I learned the hard way).

A Device With Weight

Surprisingly, Polaroid is touting the PoGo’s portability; it arrived in a custom-made jeans pocket to demonstrate the device’s pocket-sized shape. But at over 8 ounces, this thing was heavier and measured larger than Apple’s (AAPL) biggest 160-gigabyte iPod Classic. It even weighed more than a bulky point-and-shoot Kodak (EK) camera I recently tested, discouraging me from bringing it along when I went out.

A chart on polaroid.com/pogo/us/comp.html tells whether or not your mobile device is Bluetooth-compatible with the PoGo. Two out of the three devices that I tried worked: A new Motorola (MOT) Z6C and Research in Motion’s (RIMM) BlackBerry Curve were compatible, though an almost-two-year-old Motorola Razr V3 wasn’t.

Each mobile device needed only one initial “pairing,” or setup, with the PoGo before it sent photos. The device used a simple method of sending photos via Bluetooth that generally involved selecting a photo and telling the mobile device to send it to the PoGo. It usually took a few seconds for the send to go through.

The PoGo doesn’t have a display to tell users when images are received, when to load more paper or if the battery is running low. Instead, it uses two indicator lights that glow or pulse in green, orange or red colors. Each light means something different, such as whether or not the PoGo is ready to print or if it has a paper jam, but I usually had to refer to the user’s manual to figure out what each light meant.

Quiet Printer

The PoGo is rather quiet while printing, making a soft whirring sound as its thermal print head turns on and zaps dye crystals, which are embedded in the ZINK photo paper. These small pieces of paper are stored in and printed from a holding space inside the device, which saves users from opening a tray and loading paper before each print-out. However, the PoGo can hold a maximum of only 10 sheets at once. Some images printed in 45 seconds and a few took about twice that long, but most were done in about one minute — counting from when I pressed Send on a mobile device to when the print finished.

I hooked a Sony (SNE) Cyber-shot DSC-W170 to the PoGo via a USB cord and used the camera’s built-in PictBridge technology to print from the camera, following directions on the camera’s display screen. I even printed four of the same photo at once after adjusting the quantity category in a menu, though this seemed to slow the printing process a bit.

While prints from my grandmother’s Polaroid camera couldn’t be touched until about a minute after printing, the small PoGo prints come out dry to the touch. I held one under the kitchen faucet to test its waterproof claim, and the colors held up without running. These prints are borderless, which looks good but seems like the only sensible option with such small paper. Images from the digital camera looked dramatically better than those taken by mobile devices’ 1.3-megapixel or two-megapixel cameras.

Short Battery Life

The PoGo’s battery life wore out quickly, especially for a device that is advertised as portable. In one test, after I unplugged my fully charged PoGo and used it for about 40 minutes to print 16 photos — half from a Bluetooth-connected cellphone and the other half from a USB-connected digital camera — its battery indicator glowed a steady orange, meaning the PoGo was running low on power. This is about right, considering Polaroid claims that a fully charged battery will last for 15 prints. (It takes about 2.5 hours to fully charge the PoGo.)

I really liked the quality of the photos that PoGo printed from my digital camera — in fact, I’m planning to enclose a few small PoGo photos in cards that I send to friends and family members. But the PoGo’s awkward size, bad battery life and small prints make it a tough sell. I’m afraid the PoGo falls short in too many categories to be a practical gadget. Teens might like this device for printing photos from their cellphones that they can stick on lockers or books. And who knows — maybe a grandmother somewhere will buy one of these gadgets to create a little Polaroid magic for her grandchild.

Edited By Walter S. Mossberg

• Email: mossbergsolution@wsj.com

The reason it seems as if I haven’t had to charge my phone is because of a new device I’ve been using called WildCharge. This is a small, thin pad covered in panels that conduct electricity. It plugs into the wall and lies flat on a desk or nightstand, serving as a place where devices in need of a charge can be dropped, casually and effortlessly, to start juicing up.

The $59.99 WildCharge pad currently charges Motorola RAZR phones using a $34.99 adapter.

The pad, from WildCharge Inc. in Scottsdale, Ariz. (www.wildcharge.com), eliminates the messy tangle of wires that many people struggle with each time they want to charge their portable devices. But more to the point, it turns charging a gadget into something that happens in the background rather than an active task. And it spares you from that nagging question: Did I remember to plug my phone or iPod or BlackBerry in before going to sleep?

Effortless Charging

I must confess that of the hundreds of products we receive, this was one that I took home to test on a whim, thinking I’d use it once before returning it. Once I started using the WildCharge pad, I realized how much effort I put into charging all of my devices each week, and often each night. Three weeks later, this charging pad has me completely spoiled.

WildCharge isn’t for everyone. It’s a bit pricey — costing $60 for the charging pad and $35 for an adapter — especially when almost all gadgets already come with individual AC adapters. For now, WildCharge works only with Motorola Inc.’s RAZR cellphone, though in January the company will release adapters for Apple Inc.’s iPhone, iPod touch and iPod nano, as well as Research In Motion Ltd.’s BlackBerry Pearl and BlackBerry 8800.

For the WildCharge pad to work, the device you’d like to charge must be equipped with a special adapter. In the case of my pink Moto RAZR, this adapter was a black plastic piece that replaced the phone’s battery-cover panel and plugged into its charging port. I liked using the pad enough to not mind carrying a slightly thicker, two-toned phone around every day.

The idea behind WildCharge’s creation isn’t unique. For example, a company in the United Kingdom called Splashpower Ltd. (www.splashpower.com) has a charging mat in the works, according to its Web site, though the company won’t give specifics about its products.

The Massachusetts Institute of Technology takes the concept a step further with its idea of “WiTricity” or wireless electricity, which transmits power without using wires or requiring the charging object to touch anything as it refuels. Instead, this concept works by coupling two objects with the same frequency to exchange energy through the air. But this isn’t a product — yet. WildCharge is.

Thin and Lightweight

The current WildCharge weighs six ounces and its surface measures about the size of a hardcover book, though its 0.2-centimeter thickness would make it a quick read. One pad delivers 15 watts of power, allowing three to five small devices to charge simultaneously at the same speed as they would when plugged into individual wall chargers. I’d guess that about four devices, depending on their sizes, could comfortably fit on one pad.

Different Shapes and Sizes

When additional adapters are introduced in January for prices ranging from $30 to $40, these will also work with the WildCharge pad. The company also plans to sell its charging pad in various sizes and shapes next year, including a version that will deliver 90 watts, enough to power to a laptop.

Since the iPhone and iPod touch don’t have removable battery panels, they will use special adapters that look like rubber, protective sleeves. The second generation iPod nano will use an adapter that looks like a small aluminum extension of the device.

I set my WildCharge pad up on my nightstand. After a phone chat, I tossed my RAZR cellphone over to the charging pad; four magnetic contact points on the phone’s adapter helped it stick to the pad. A chime indicated my phone made electrical contact and started charging (the same sound I normally hear when I plug it into its AC adapter cord). A tiny blue light on the pad indicated a device was charging. I really grew fond of not hunting for the correct cord to charge my phone. Instead, I’d finish conversations, reach over and simply drop my phone down as if I was laying it on the table.

Likewise, if I walked in the room after a chat, I’d set it down for a few minutes before leaving and taking the phone with me. Charging didn’t have to be an event; it wasn’t even a conscious effort.

Once in a while when I’m running out of battery in the middle of a phone chat, I’ll plug my phone into its power cord and continue talking. This isn’t possible using the WildCharge because the phone must lie on the pad, face up. However, you could use a BlueTooth headset or switch to speakerphone. (I tried the latter without a problem.)

Easy to Pack

I imagine that WildCharge made its pad for stationary usage rather than for portability. But after becoming so accustomed to WildCharge, I couldn’t resist taking it home with me over Thanksgiving, and its flat panel and AC adapter were easy to pack.

WildCharge Inc. says its charging pad won’t be damaged if most liquids are spilled on it. I wiped water off with a cloth and it was fine. Other electronics won’t be affected if they’re placed on the device, and it doesn’t use radiation or magnetic fields to charge devices.

Right now, no matter how slick your portable media player, smart phone, laptop or digital camera, it’s still enslaved to its power cord. The WildCharge pad cuts out the cord and lets forgetful, busy people stop worrying about plugging in each of their devices. WildCharge would be improved if its adapters were built into phones.

Even more exciting is the thought of public places using WildCharge or similar technology so that when you can walk into a restaurant, you can rest your cellphone on a table and have it powering up in the background. Now that’s something we can all get a charge out of.

Email mossbergsolution@wsj.com.

VTech Communications wants to put an end to this mad phone dash with its new $150 Expandable Cordless Phone System with Bluetooth, the LS5145. This device synchronizes with your cellphone and redirects incoming cell calls to ring wherever the VTech phones are placed in the house. It works with your landline and up to two Bluetooth-linked cellphones, and can be expanded using additional handsets that cost $80 each.

The $150 Expandable Cordless Phone System with Bluetooth from VTech Communications Inc.

The concept of a cellphone extender isn’t new, but not many of them have caught on. Another popular add-on to cellphones at home is the repeater, which focuses on boosting a phone’s signal in a place with poor coverage. The VTech 5145 could work as a repeater, assuming you put it and the finicky cellphone in a place with good coverage. But if your entire house has lousy cell coverage, it won’t work as a repeater.

AT&T licenses its corded and cordless phones through VTech, which sells a less-expensive product similar to the 5145 called the AT&T EP5632. It costs $100 and has the same basic functions as the 5145, but is clunky and much less stylish. Its additional handhelds cost $60 each.

This week, I put my feet up and tried the VTech 5145 and one of its accessory handsets, the LS5105. These phones are stylishly thin and have bright color display screens, which can be set to one of 27 still color wallpaper images or four animated designs. It took me only a minute to pair cellphones with the system using Bluetooth, a wireless technology that connects devices that are within about 30 feet of one another. And the VTech’s primary function — extending the cellphone throughout a house to make it more convenient to answer — worked well, ringing much louder than my cellphone.

But the 5145 didn’t display the numerous names and numbers stored on my cellphone’s contact list. Unless I wanted to painstakingly enter the data into the VTech, incoming calls were only identified with phone numbers, so I rarely knew who was calling. And I could only call the handful of numbers that I know by heart.

Bluetooth technology isn’t incapable of transmitting data: My BlackBerry Curve even tried to transfer its contacts to the 5145, but couldn’t. VTech chose to use headset Bluetooth synchronization on the 5145 rather than hands-free synchronization. Hands-free is the same technology used in most Bluetooth-equipped cars; it provides more access to the Bluetooth device, such as phone-book integration.

I also missed other features on my cellphone when it wasn’t by my side, such as text messaging and voice mail. Incoming text messages were sent to my cellphone unbeknownst to me since I wasn’t near it, and when I didn’t answer incoming calls through the VTech, I had no way of knowing if the caller left a voice mail on my cellphone.

The 5145 includes a base station and primary phone; the 5105 additional handset includes a small stand just big enough to hold it upright. I set up the base station near where I drop my work bag after coming home each night. After the initial pairing during setup, phones automatically link to the VTech, meaning I never had to take my cellphone out of my bag.

I paired the 5145 with two phones at once: a Motorola Razr using Verizon and a BlackBerry Curve with AT&T service. I also tested pairing a third phone with the system, the HTC Pocket PC 6800 from Sprint, though only two cellphones can be paired simultaneously. Just one of the Bluetooth phones can be used at a time, in addition to the landline. As long as the two paired phones stayed within about 30 feet of the base station, they automatically started routing calls through the VTech.

Call waiting worked like using my actual cellphone, except I pressed different buttons on the 5145 to “swap” calls. If you’re chatting on a landline call, you can answer an incoming cellphone call by placing the landline call on hold. If each line — landline and cellular — has call waiting, a total of four callers could potentially be linked to the VTech system at once.

In my house, we gave up our landline years ago, so I tested the system using only cellphones. I saved myself a few trips racing up and down the stairs to find where I had left my cellphone, instead placing the base station on one floor and the additional handset on the other. Using cordless phones for the first time in years reminded me of the issues that accompany this system. The line became fuzzy when I moved too far away from a phone’s base station, though VTech says a connection can stay clear for up to about 900 feet.

I almost forgot that cordless phones can’t be taken out of the house. While on a phone call, I had to stop myself from heading out the front door and continuing my chat as I walked to the corner store. Cellular calls that are in progress on VTech handsets can be continued on the cell by adjusting a setting on the cellphone, or by walking far enough away from the base station to receive a cellphone prompt to disconnect from the system.

I made calls from the handsets by first choosing which of the paired cellphones to use. My calls were received by friends and family just as if I was calling on my cellphone, though a couple of people told me that the connection didn’t sound quite as good.

Each handset is equipped with a speakerphone, and missed calls are noted on the color screen and in a call log, along with the date and time. A built-in intercom system lets handsets communicate with the other or the base station. Users can choose from one of 23 ringtone-like melodies; I chose a steel drum tune for one handset.

If you’re looking for an easier way to answer your cellphone whenever and wherever it rings, VTech’s system might be a good solution for you. But if you rely on your cellphone’s address book to identify callers and aren’t up for inputting these data again, it might be worth waiting for a Bluetooth cordless phone system that will automatically copy data from your cellphone.

Edited By Walter S. Mossberg

• Email mossbergsolution@wsj.com

But what about when you need directions and you’re unable to get to a computer? The same companies that you look to for directions on your home PC are eager to help out on your cellphone, including Google, Yahoo and MapQuest. But while the mobile versions of these services are improving, the user interface of a cellphone isn’t ideal for inputting addresses and extracting directions. Even smart phones with larger screens and full keyboards can be hampered by slow Internet speeds.

This week I tried a service that cuts the time it takes to get directions from a cellphone. It’s called Dial DIR-ECT-IONS, and it works as it sounds: You dial the word “directions” into a cellphone (347-328-4667) and speak the address, name of business chain or event to which you need directions. Step-by-step directions are instantly sent to your phone via SMS, or text message.

This isn’t a substitute for phones that have GPS and can give real-time directions, and it may not be ideal for those who need visual cues, like turn-by-turn maps, but it is very convenient on the go and works on any basic cellphone.

The service, from a determined start-up called Dial Directions Inc., is free — except for the cost of receiving text messages on your phone. After the first 30 days of use, a one-line advertisement will start appearing at the bottom of the last text message sent per set of directions (some take multiple text messages to include all of the steps).

In many instances, I found using Dial Directions to be helpful and efficient, a welcome change from squinting to see miniature maps on cellphone screens. It’s smart enough to ask you if you know how to get to the highway, thus saving you from reading directions you already know. I tried the service with a few different cities — you don’t have to be in the city to use it because GPS isn’t involved — and valued the instant gratification of returned results with so little effort.

Dial Directions is still a work in progress. The service prides itself on superb voice-detection technology, but in one instance, it interpreted “New York City” as “Newark, N.J.,” and didn’t stop to check the accuracy of this, forcing me to hang up to restart. And the two other aspects of the service, finding business chains and events, need just a little more time to include a better variety of businesses.

The service was launched in July, but this week marks its expansion to nine metropolitan areas, including New York City, Washington, D.C., Chicago, Dallas, Denver, Los Angeles, San Francisco, San Diego and Sacramento, Calif. The service still isn’t in major cities like Boston and Philadelphia, but these cities and others will be included within the next month, in the company’s attempt to take the service nationwide.

Dial Directions also plans to add landmarks in the next month. I tried asking for directions to the White House and Yankee Stadium without any luck. General terms will also be better integrated into the service. I tried saying “movies” but Dial Directions thought I was saying “Mervin’s” one time and “Arby’s” the next. Just 40 terms, including “hotel” and “gas station,” are usable right now.

I called Dial Directions from a Motorola Razr cellphone, a Research In Motion BlackBerry Curve and an Apple iPhone. All worked well. Since SMS messages are limited to about 160 characters, regardless of your phone, none of the directions came through in just one message; most directions required from two to five text messages. Symbols help to shorten the messages, like using “L @ Maryland Ave. SW” to tell a user to turn left at Maryland Avenue Southwest.

To receive these directions, you must first tell the service what you’re looking for. The female voice representing Dial Directions is friendly and doesn’t sound stiff and robotic. She offers to give instructions on how to use the service if you don’t know how. After telling her what you’re looking for, she asks what city you’re in and where you’re trying to go.

I tried a variety of addresses and intersections; the system suggests not saying “Street” or “Avenue.” In certain instances when a highway was involved, I was asked if I knew how to get on the highway, and if I did, that extra text wasn’t included in my directions. Once I confirmed what I was looking for, the voice said directions would be on the way in a couple of text messages. Each time, they appeared on my phone almost instantly.

In the case of business chains or general terms like “hotel,” the voice told me first of the closest one it knew, asking me to confirm whether or not it had found the right place. If I said no, it suggested four more that were the next closest. This worked well in most cases, including searches for McDonald’s, Bloomingdale’s, Starbucks and pizza. However, in a hunt for the closest Dunkin’ Donuts, it couldn’t find four stores that were located a mile from my office in downtown D.C.; instead, it thought the closest one was in Arlington, Va.

The company pledges that this and other faults will be improved over the next month as its database is improved and as more users report issues that can be corrected.

Directions to local events can be retrieved as long as the event is posted on DialDirections.com. Then anyone can just say the name of the event (like “DC Shorts Film Festival”) to receive directions to that event. But this feature, too, isn’t what it should be right now. On my way to a Washington Nationals game, I couldn’t get the service to recognize the name of my event, which was frustrating.

If the company can correct some of its hit-or-miss aspects, this free service could be a big help, especially for people who don’t own smart phones. But even if you do own a smart phone, it’s faster than typing in data and waiting for a Web browser to retrieve the directions. If this service can improve its ability to find nearby businesses, this alone could be really useful.

When it knows about more locations, Dial Directions will be a great service. As it stands now, it’s helpful for directions from one address to another in certain areas. Sometimes, the most straightforward solutions really do work best.

Edited by Walter S. Mossberg

• Email mossbergsolution@wsj.com

Today, things are different. Many parents buy cellphones for their preteen children to keep in touch and as a safety measure. Teens have the luxury of their own cellphones that some parents won’t even know how to use.

But cellphones introduce a host of problems. Parents have no way of knowing with whom their children are talking or text messaging, nor do they know what is being said in these calls or in text messages typed in abbreviated slang. Digital photos and videos can be captured and sent from one phone to another in seconds, and smart phones with Web-browsing capabilities bring the Internet and instant messaging to kids wherever they are.

Mobile alerts, which can be received via email or text message, are useful for on-the-go parents.

This week, I tested a new software application called Radar that can be wirelessly downloaded onto a kid’s cellphone to digitally monitor the phone’s activities, including incoming or outgoing calls, emails and text and photo messages. Alerts are sent notifying parents of any contact with unapproved people.

Radar comes from eAgency Inc., Newport Beach, Calif., and is geared toward 8- to 14-year-olds. Though Radar doesn’t yet work on the most basic cellphones and has limitations, including not notifying parents when a child uses a phone for Web browsing or instant messaging, eAgency says these improvements and others are in the works for future versions. Overall, Radar performed well and was user-friendly enough for tech-shy parents.

The company charges a monthly fee of $10 for one user or $15 for a family, which enables monitoring of up to five accounts. There’s no limit to the number of people who are alerted to a phone’s activities, as they don’t need to download Radar. Instead, notifications are sent via text message and/or email to a parent’s mobile device; they’re also collected on a Web site where all activities are listed together.

EAgency is careful to note that its software application isn’t spyware, lurking in the background of the device without making itself known. In fact, whenever the child’s phone is turned on, a message says it’s being monitored by Radar. This message also appears on the phone once daily.

For now, Radar only works on all BlackBerrys regardless of carrier, and eAgency has a deal on its www.MyMobileWatchdog.com site that can get BlackBerry Pearls free of charge for certain customers. But many parents’ kids already have basic cellphones or don’t want their kid to have a BlackBerry. In roughly a month, Radar will work with devices that run Microsoft’s Windows Mobile software, though this doesn’t help much, as these devices function more like BlackBerrys. Radar will be available for regular cellphones, like Motorola’s Razr, by mid-September.

I tested the product using a BlackBerry Pearl as the kid’s device and an LG Chocolate phone as the parent’s device that would get alerts of phone activity. To get Radar running on the Pearl, I sent a text message with a download link in it from the company Web site, and loaded the application onto the BlackBerry in a few seconds.

I used the Pearl as anyone might, adding names, numbers and emails of new friends and contacts that I wanted stored in my BlackBerry. I also used it to make and receive calls, and to send and receive emails and text messages. Every time any of these activities took place with an unapproved person, the parent phone was notified within seconds, as was my account on Radar’s Web site and the email addresses that I set up with my account.

Unknown people are automatically considered unapproved until you go onto the Radar Web site to change their status in your account. I accessed this account on MyMobileWatchdog.com with a username and password. EAgency asks that you call the number on its Web site the first time you set up a Radar account so that it can walk you through how the software application works with your child’s phone.

The account home page on Radar’s Web site is a clean space, organized using tabs at the top and six shortcuts in the center of the screen, including “Alerts,” which shows a comprehensive list of all the alerts.

Alert notifications are simple, stating who did what, when it was done, and what the message or call involved, such as the content of a text message or the documented length of a phone conversation. Radar won’t record phone conversations. Mobile alerts can be received via email (on a smart phone) or text message (on a regular cellphone or smart phone).

After using Radar for a few days, I realized some text message alerts were truncated due to the SMS standard that limits messages to 160 characters. So though your child might send a message with 100 characters in it, your alert might contain only 90 of those because characters are used up by notifications such as, “Katie has received an unauthorized text message from…”

Radar’s Web site offers a text message abbreviation dictionary so you can decipher what your kid is actually saying when he or she types “JTLYK” (just to let you know).

During testing my BlackBerry Pearl received an MMS, or Multimedia Message Service, containing a digital photo. My parent phone and email account were notified through a message with a link to this photo.

Alerts are also generated whenever a child adds a new contact to his or her device. A list of the most recent contacts added to the child’s device conveniently appears on the Radar account home page. By marking someone as “Approved,” a parent agrees not to be notified of contact between that person and the child. People marked as “Unapproved” and “Suspicious” will generate alert notifications.

Reports documenting your child’s interaction with specific people over certain time periods via text, email or voice calls can be generated at the click of a button. These reports can be printed out or digitally exported from Radar’s site using Internet Explorer as your browser.

For $10 or $15 monthly, Radar might be worth a try, especially with very young kids. But until Radar is available for the phones most popular with kids, parents will have to continue with their tried and true methods of keeping track of their kids’ phone use.

Edited by Walter S. Mossberg

• Email: MossbergSolution@wsj.com