On a chilly day, most folks find it tough to open the front door to retrieve the newspaper — much less climb a 15,000-foot mountain. But plenty of people court danger by rappelling down canyons and camping in remote woodlands. This week, I tested a device that will give thrill seekers a little extra insurance: It lets the folks back home track their progress, and learn when they’re OK or when they’re in trouble.

When activated, the $170 SPOT Satellite Messenger from SPOT Inc., the Milpitas, Calif., unit of Globalstar Inc., emits a signal to GPS satellites, which notify SPOT’s messaging service. The service then sends a message to friends, family or emergency rescue teams about your current status. Because it uses GPS technology, the SPOT will work even when you’re far from cellphone signal range and anywhere in the world.

I tested SPOT in my Washington, D.C., neighborhood (city parks still count as outdoorsy) and on a trip across the California desert and mountains on the way to a conference — though I was scaling mountains in an air-conditioned SUV rather than in a rock-climbing harness.

In my tests, SPOT worked without a problem. Notifications from the device were delivered to my friends via email and text message and included my current latitude and longitude. The service also sent along canned messages that I set up in advance on the company’s Web site at www.findmespot.com and hyperlinks to Google Maps that showed my location.

SPOT charges a $100 annual service fee, which includes an unlimited number of messages that can be sent out from your device using three buttons: OK/Check, Help and 911. An additional $50 per year tracking service called SPOTcasting follows and marks your exact location every 10 minutes for 24 hours each time it’s initiated.

This simple and straightforward device could really help in a dangerous situation. And the company takes its job seriously: A steely message on the SPOT packaging reads, “Opening this box is the first step in making sure you don’t come home in one.” But SPOT could also save the day in less-adventurous situations, such as when your car dies and you’re out of cellphone range.

However, SPOT isn’t perfect. While its three message-sending buttons make it easy to use, they also limit the types of messages it can send. There’s no keyboard, so messages must be brief and set up in advance on the Web site. And the device only sends messages and can’t receive them. Your friends and family have no way of getting back in touch with you on SPOT should you send a Help message from beyond cellphone range.

SPOT is a bright orange device with roughly the same surface measurement as a BlackBerry, though it’s considerably thicker. Its durable casing makes it waterproof and floatable, along with working in extremes like -40 degrees Fahrenheit and up to 21,000 feet above sea level. It runs on two AA lithium batteries, which last for different amounts of time according to the type of message being sent.

Setting up SPOT took only a few minutes on the Web site. A default or personalized message can be set up to go out with OK/Check and Help notifications, and email addresses and cellphone numbers (for SMS text messages) can be entered online as the destinations for these messages. Every message includes the user’s current location in terms of latitude and longitude, along with a hyperlink to access that location via Google Maps.

SPOT sends messages and location information via satellite, including points that can be tracked on a map.

The OK/Check button can be used most casually by owners of this gadget, as it merely serves to assure others that you’re fine. A good example might be two people on a three-month sailing trip who use this button as a means of checking in with family every Sunday night.

If OK/Check is held down for five seconds, it initiates the SPOTcasting tracking service (provided you’ve signed up for it) and locates your device every 10 minutes for a 24-hour period. These tracked points show up on SPOT’s Web site and are displayed as numbered points on Google Maps.

SPOT worked for me while driving through a regional park with a campsite, where cellphone range was faint, and up into boulder-crusted mountains. Just minutes after pressing Help or OK/Check or initiating tracking, friends received word of my location via emails and text messages.

You can’t set SPOT to track a trip for longer than 24 hours or at different intervals, such as every hour for a week. And the only way for others to view your tracked points is if they sign in using your online account’s username and password.

The Help button is used in more urgent situations and uses messages such as “Urgent help needed. Pick me up at campsite.” (The default for Help is “This is a HELP message. Please send for help ASAP.”) But preset messages shouldn’t be made too specific during the online setup because they can’t be changed from the device later.

The 911 and Help automatic notifications will always override less urgent messages like OK/Check or SPOTcasting. In the case of the 911 and Help buttons, one can be pressed after the other and the messages for both will still go out at the same time. The 911 button will send a message every five minutes until power runs out (the company says this will last for up to seven days) or until the message is canceled; Help sends a message every five minutes for an hour or until canceled.

The 911 button is more serious. When pressed, SPOT Inc. automatically notifies a certified 911 company called the GEOS International Emergency Response Center, which contacts your specified emergency contacts first to see if they know anything about your situation before dispatching a rescue squad using your coordinates.

If you can adjust to SPOT’s three-button approach, the device could be helpful for you or someone you know during outdoor adventures. Many people will buy SPOT simply for its 911 button, as an insurance policy on fluky cellphone service.

• Email mossbergsolution@wsj.com

Corrections & Amplifications:

The SPOT Satellite Messenger uses a global positioning system to determine a user’s location and a second satellite network to send notifications to friends, family and emergency services. This column erroneously stated that GPS satellites send notifications.

Owners of the $399 iPhone can get a free update, but those with the $299 (8 gigabyte) or $399 (16 gigabyte) iPod touch must pay $20 for their update because Apple tracks revenues differently for iPhones compared with its iPods.

Updates for the iPhone and iPod touch add Web bookmarks to the home screen and a redesigned Maps application that displays a user’s current location.

This week, I’ve been using an iPhone and iPod touch with these updates, and I must say that both devices are much more useful and fun with these improvements. Web clips, or browser bookmarks that take the form of icons on the home screen, give these gadgets a new sense of instant gratification because they direct users to specific Web pages seconds after the device turns on. These little icons can be labeled and moved around, letting you group favorite Web sites on one screen, games on another screen, saved Web research on a third screen and so on.

Getting Synched

Both devices can be updated by synching with iTunes; the iPhone does so automatically and the iPod touch updates only if the owner buys this upgrade through the iTunes Store. New iPod touches include the updated software free.

New to both devices is a redesigned Maps application that, at the touch of a button, displays a user’s current location in an on-screen map — without using Global Positioning Systems. Other non-GPS devices currently do this, but they depend solely on cellphone towers to determine your spot. The iPhone uses both cellphone towers and nearby Wi-Fi hot spots to find your location; the touch uses only the Wi-Fi method.

The iPod touch also now has the same stellar Mail program that is found in the iPhone, a real plus for owners who have been curious about mobile email but weren’t necessarily ready to plunge into a BlackBerry or iPhone, or don’t want to pay for a monthly data plan.

Both devices can store numerous Web clips on up to nine different home screens, each of which has room for 16 icons. A handful of permanent applications appear by default on the main home screen, but these can be shuffled around. Along with Maps and Mail, applications for Stocks, Weather and Notes were also added to the iPod touch.

Multi-touch technology only improves these new features. For example, home screens are easily navigated by flicking a finger horizontally to get from one to the next. Holding a finger on any Web clip causes all of them to jiggle like tiny pieces of digital Jell-O, waiting for you to either delete or drag them around wherever you would like them to stay. Pressing the Home key cements the icons in place.

Trouble Finding Home

But these updates left room for improvement. Maps had trouble on both my iPod touch and iPhone when I asked it to find me in my home in Washington, D.C., and in my office near the White House — the former test circled a 30-block radius while the latter marked me four blocks away. Tests in other locations worked well, and clever “Drop Pin” tools helped me mark and label specific places. But I wouldn’t rely on this feature if I was completely lost and hoping the iPhone or iPod would tell me where I was.

And though I was excited to have email on my iPod touch, this device lacks a speaker and vibrating capabilities, so it can’t chime or buzz to signal newly received email. Because of this, the touch wouldn’t work for me as a serious, everyday tool like the BlackBerry and iPhone.

The free update for the iPhone lets you text message multiple people simultaneously, something the most basic cellphones have been doing for years. But individual responses to these mass texts can’t be seen in the same thread of conversation as that which you started; instead, they generate new text message threads.

On the iPhone and iPod touch, the Maps application now shows hybrid views that combine satellite maps with labeled street names, which are helpful.

The iPod touch is a testament to what can be done on a mobile device without a cellphone carrier’s help. By tapping into Wi-Fi hot spots, which are almost everywhere, I easily checked email, stocks and weather. I had a little more trouble using the Maps application with Wi-Fi because I was more often checking my location while on-the-go in a car or walking.

Collecting Web Clips

I had fun populating the many screens of my iPod touch and iPhone with new Web clips. These are easily added by hitting a “+” symbol at the bottom of any Web page, naming the Web clip and watching it appear on a home screen, often with a colorful accompanying icon like that for AllThingsD.com.

Snapshots of a Web page can be captured and saved in a Web clip by zooming in on a certain section of a page and saving that specific view. This proved helpful when I needed to quickly glance at the Georgetown basketball schedule a few times in one day.

Web applications can be found at www.apple.com/webapps. A game called Ditto involves repeating a pattern on blue, yellow, red and green squares using the touch screen — a digital version of the Simon handheld game. Memory, the old card game, is updated with animated animals on cards. FlyTunes lets users listen to customizable channels from Internet radio, while an app called Floort presents an opinionated topic and asks people to vote on whether they agree or disagree. Even simple Web apps were useful, such as one that turns the screen into a virtual ruler with inches on one side and centimeters on the other.

But it’s good to keep in mind that these are Web applications, and are useless without the Web and/or an AT&T connection.

All in all, Apple’s software updates for the iPhone and iPod touch are exciting, especially because they make home screens much more useful and individualistic. These tiny devices continue to become truly mobile computers.

• Email mossbergsolution@wsj.com.

Digital Cameras

Megapixels: This term describes the highest resolution photo a camera can take. Often mistaken as the most important factor in a digital camera, a high megapixel count — such as 10MP or more — isn’t necessary for the average user unless he or she plans on heavily editing or enlarging photos. Most new digicams offer between five and eight megapixels, which is usually more than enough.

Optical or Digital Zoom: Optical zoom, determined by the physical movement of a lens, matters much more than digital zoom, which digitally alters an image using the camera’s internal computer. Camera companies still try to confuse potential buyers by listing a camera’s total zoom, or the optical and digital zooms multiplied together. Ignore total zoom numbers and instead focus on optical, which now averages around 5x for many new cameras.

Image Stabilization: When generously sized LCD viewing screens started replacing optical viewfinders, they also forced users to hold their cameras at arm’s length, making for plenty of blurry photographs. To remedy this, camera manufacturers have added image stabilization, tools once found only in high-end SLR models. Optical (also called “mechanical”) and digital image stabilization correct for unsteady hands and moving subjects, respectively. Cameras with both types advertise dual image stabilization, which corrects for both situations and costs more.

Mobile Devices

HSDPA and EVDO: HSDPA, or High Speed Downlink Packet Access, is the name for AT&T’s 3G, or third generation, mobile network that operates at roughly the speed of a slower DSL in a home. HSDPA is available in most major metropolitan areas and is seen as the competitor to Verizon and Sprint’s EVDO (Evolution Data Only) networks, though the popular iPhone runs on AT&T’s network using Wi-Fi and EDGE technology rather than HSDPA.

Multi-Touch Technology: Most popularly found on Apple’s iPhone and iPod touch, multi-touch is starting to show up in other products, such as in Microsoft’s Surface, a coffee-table-like computer. Rather than just responding to on-screen touches, this technology enables moving, resizing and zooming pictures and Web pages using one or more fingers simultaneously. Look for many more devices — mobile and otherwise — to incorporate multi-touch in the future.

GPS: Global Positioning Systems are most often found in cars — either built-in or on portable devices from companies like Garmin and TomTom. These gadgets use satellite technology to determine geographic location, and high-end models even display Web content like news and weather along with directions. GPS integration in mobile devices can be used to plot routes in cars, can help users find nearby businesses while on the go and can link friends by showing one where the other is located and what they’re doing.

Digital Music

DRM: Digital rights management is a set of standards that protect the intellectual property rights of online content like music and videos, preventing it from being illegally distributed across the Web. In the past year, Vivendi’s Universal Music Group, Apple and (most recently) Sony BMG said they will start selling DRM-free versions of songs, often for a higher price. In Apple’s iTunes store, these files are called “iTunes Plus” and aren’t restricted like other iTunes content.

MP3: MP3 files are open, without any DRM restrictions. Files that you rip (copy) from your own CDs are usually converted into MP3s, though iTunes users can automatically rip tracks into that program’s special format, called AAC. MP3 files can be uploaded to social-networking sites for sharing with friends and online communities.

These file types are protected by rights that tie them to specific players. Generally, AAC files make up the majority of tracks sold on Apple’s iTunes store and play only on Apple’s iPods; WMA files are Microsoft’s version of proprietary files.

Wi-Fi

The popularity of Wireless Fidelity, or Wi-Fi, brings this technology to more and more portable devices like the iPod Touch and Microsoft Zune and gives companies good reason to incorporate Wi-Fi receivers in new computers — laptops and desktops alike. While available in many flavors, different letters like b, g, a and n stand behind Wi-Fi’s more technical name, 802.11, to help discern one version from another according to characteristics like speed and compatibility. The latest version, “n,” offers the greatest range and speed, and “n” devices are usually compatible with earlier versions.

Televisions

HDTV: High-definition television has now become the standard, capable of displaying vastly better pictures, provided the source is also HD. Today’s more popular flat panel HD televisions are LCDs, or liquid crystal displays, though plasmas still hold their own. Recording HD content can’t be done with a regular digital video recorder; instead, a special HD recorder is required to capture this higher quality content.

480p vs. 1080i vs. 720p vs. 1080p: These numbers refer to the resolution, or sharpness, of a digital display, while “p” stands for progressive and “i” stands for interlaced. A resolution of 480p, known as EDTV or Enhanced Definition TV, is found most often in low-end plasmas or LCD screens. A TV with a resolution of 1080p is currently considered the Holy Grail, and costs the most. But 1080p pictures usually can’t be distinguished from less expensive 1080i or 720p pictures by average viewers at the typical distances from which most folks watch TV.

Blu-ray vs. HD DVD: Blu-ray and HD DVD are incompatible high-definition disc formats that continue to fight a seemingly endless battle to replace the DVD. The Blu-ray camp is led by Sony and the HD DVD camp is led by Toshiba. The two formats aren’t so different, technically speaking, but their very existence is confusing to consumers. The recent decision made by Time Warner’s Warner Bros. to use Blu-ray gives Sony’s side a boost, and now Viacom’s Paramount is rumored to be switching to Blu-ray from HD DVD. Dual-format players from Samsung and LG offer some solace.

Email: mossbergsolution@wsj.com

Great songs, like chocolate-covered strawberries, can be sampled once and adored immediately. This is good news for online digital-music stores, where anyone with an Internet connection and a buck can log on from a computer and download a new favorite tune seconds after hearing it.

Now, XM Satellite Radio Holdings Inc. is making this audio gratification even more instant. Last month, it introduced the first portable combination XM radio/MP3 player, the $400 Pioneer Inno XM2go. Anyone with this device who likes a song playing on XM can simply press a button and record the entire song onto the player. No computer is required, but you do need an XM subscription, which costs $13 a month.

The $399.99 Pioneer Inno XM2go combines portable satellite radio with a digital music player, but watch out for reception problems.

These recorded songs can’t be transferred to PCs or other players. But they can be bookmarked for purchasing online at Napster’s music store the next time the Inno is plugged into a Windows computer. This purchased version of the song can be used on computers and other devices (but not the Apple Computer Inc. iPod).

The new XM device, made by Pioneer Corp.’s Pioneer Electronics (USA) Inc., uses flash memory rather than a hard disk, and can store 50 hours of recorded XM Satellite Radio, plus about 8 hours or 150 digital songs copied from a computer. One half of the player is reserved for XM recordings, while the other half is reserved for MP3 or WMA music files. You can switch between the two modes by pressing a button.

The Inno is at the center of a lawsuit filed yesterday by members of the Recording Industry Association of America, who are challenging the legality of the device’s recording feature.

This week, we tested the portable Inno all around town. We liked the device itself, and enjoyed listening to various satellite radio stations on the go. But we were deeply disappointed with its radio reception, which failed in too many places. And we really didn’t like working with the Napster software when we synched the player with our PC. It was a hassle.

Our verdict: adding live satellite radio and the ability to record it onto a device is a good idea, and may appeal strongly to satellite radio lovers willing to pay $13 a month to subscribe. But, for people who just like music, the radio and recording features didn’t seem like reason enough for us to want to buy the Inno over, say, an iPod — especially given the downsides we encountered.

We liked the overall feel of the Inno, and it wasn’t too tough to get the hang of its buttons and functions. It measures 3.7 inches by 2.2 inches by 0.6 inches — just slightly smaller, overall, than a full-size iPod and a little bit thicker — and its 4.5-ounce weight makes it a tad lighter than a 30-gigabyte iPod. A 1.7-inch color screen on the front doesn’t take up the entire surface, and compared to an iPod’s 2.5-inch color screen, its size was more like the one on the tiny iPod Nano, a 1.5-incher.

The back and front sides of the Inno are decorated in cool gun-metal gray. Shiny black edges give it a modern feel, while its stubby antenna resembles that of a smart phone, but thicker and perfectly cylindrical. This antenna is the device’s only means of receiving radio. That’s a breakthrough, since satellite radio usually requires a large separate antenna or a car antenna. Unfortunately, we found the Inno’s little antenna was too weak.

It’s hard to overstate the reception problems that plague the Inno. We lost reception while driving through a short tunnel, walking through a row home and wandering through our office, away from the window. Even in an office with an entire wall of windows, we had to sit right next to the glass to get XM Satellite Radio reception.

Walking around downtown Washington, just a few blocks from the White House and a few miles from XM’s headquarters, the Inno constantly dropped the XM signal, even though Washington, by law, has no office buildings taller than about 12 stories. Walking just a few feet into a Starbucks killed the signal altogether. When we sat down on a bench in a small park, the reception got much better, but still wasn’t perfect. For a device that’s primarily a radio, this is a killer flaw. Of course, you can listen to the Inno’s stash of recorded music during these signal dropouts, but, when the failures are as frequent as ours were, this need to keep switching modes turns a supposedly pleasurable experience into a huge annoyance.

Optional headphones with an antenna disguised in the headpiece can be purchased for an additional $40, and these added slightly better reception, but not much.

A well-designed button on the right side of the Inno powers it on or off when pushed downward, and puts the device on hold when pushed up. Volume controls are just below this button, also on the device’s side. Three buttons line the bottom edge of the color screen — Mode, Play/Pause and Display — and four directional arrows surround an XM select button below these three.

We checked out XM’s 20 categories of music, over 170 stations altogether, by pressing the right arrow button. We paused in the Decades category to listen to “Sunshine Superman” by Donovan on the ’60s station before skipping to Hits where Daniel Powter’s catchy new pop song “Bad Day” was playing on the “Top 20 on 20″ station.

To record “Bad Day” onto our Inno, we pressed the XM button, chose Record and Record Song. A red “REC” icon appeared at the top of the screen, and went away when the song ended. In one case, we were listening to a station when a new song that we wanted to record started before we could press the right buttons. Thanks to the magic of satellite radio, recording automatically started at the song’s beginning, rather than halfway through.

If you’d like, you can schedule times for your Inno to start and stop recording, and these can be set to record on the current day, every day or on a specified date.

When listening to Elton John’s “Something About the Way You Look Tonight” on a romantic music station appropriately named “The Heart,” we opted to Bookmark the song so that it was set aside in a special category of songs for buying when we connected our Inno to our PC. An option called TuneSelect can be chosen while a song or artist is playing; from then on, a message will flash across your screen whenever that artist or song plays anywhere on XM, so you can tune in.

Before synching our Inno with our computer, we used an included CD to load XM + Napster software onto our Dell PC and typed in a special promotional code given to us by Napster for testing.

The Napster software program is confusing, to say the least. Napster offers three types of accounts: Napster Lite, music-store usage with no monthly fee that allows online listening and purchasing of songs à la carte; Napster Membership, a $9.95-a-month program allowing unlimited music downloads onto the PC — but not for transferring to a player; and Napster To Go, a $14.95 monthly membership that allows unlimited music downloading and transferring to a device.

If that doesn’t confuse you, add the fact that because Napster offers music rentals rather than just buying of songs — like iTunes — it considers purchased tracks to be different than downloaded tracks. Overall, your purchased tracks or previously owned tracks (in MP3 or WMA file format) can be transferred to the XM2go. Downloaded (not purchased) tracks can’t be transferred to the XM2go, but they can be transferred to special, more advanced devices with what’s known in techie land as DRM 10 compliance. XM plans to introduce devices with this technology in the future.

The Inno connects to a PC using a standard USB cable, but it must be simultaneously lying in its special sideways dock, which also powers the device. When the Inno is turned sideways in its cradle, its screen automatically rotates, as do its directional arrows. This cradle also has plugs for an additional included antenna and a line out, for using the Inno with a stereo system.

In Napster’s software program, our Inno was identified, as were the songs that we had recorded and bookmarked. Songs recorded from XM can’t be exported from the player, due to copyright laws. Most of the songs we had bookmarked, including Elton John’s tune, had a Download icon next to their track titles.

But instead of seeing a Buy icon next to our bookmarked tunes, we could only purchase songs by right-clicking on tracks and choosing Buy Track since our account type was designed for streaming music rather than buying it. This type of navigational confusion was abundant in the program, and users would easily and understandably be befuddled by what account type they had and what was or wasn’t included in it.

We dragged and dropped songs onto our Inno player without a problem, and they showed up in the MP3 section of the player when we started it up again. We even created playlists, right on the Inno, combining music recorded from XM stations and our own MP3s. Switching between the live XM stations and our MP3s and WMAs was easily done with the Mode button. XM estimates that the Inno’s battery will last for 15 hours in playback mode and five and a half hours in Live XM Mode.

When it’s all said and done, XM’s Inno is fun to use on the go, as long as you’re not underground or in room without windows. But its spotty reception, confusing software and monthly fee make the Inno a no-go, except for hard-core XM fans.

• Email: MossbergSolution@wsj.com