I grew up on classic FM rock radio. (Yes, I'm a dinosaur from the ancient Boomer Age.) The late 1960s and 1970s encompassed a golden era of musical diversity on the airwaves; a multiplicity of bands, styles and vernaculars appeared on eclectic, free-form playlists that were leavened liberally with B sides, live versions, alternative recordings and obscure ditties. And then there was the mystery factor: you never really knew what was cued up next, not until the first bars sounded. But when the DJ struck the right vibe for your mood with an unexpected gem, it was pure magic.

Today FM radio is a wasteland--repetitive, overprogrammed, market-niched to the max, seemingly with more commercials than music. The only strategy that makes it somewhat bearable is to keep switching among several preprogrammed stations, a frustrating enterprise that gets tough on the index finger.

Then there's the portable digital music player--iPods, MP3 players and the like. What's not to love? Nearly distortion-free recordings of your favorite songs (presented randomly if you choose) to listen to anywhere you like. The players require a bit of work to produce your personal soundtrack, but not much. Of course, there is no way around the fact that you are always playing your favorites. And as anyone who has owned an extensive collection of LPs, cassette tapes, CDs or iTunes knows, listening to even a large set of well-loved recordings can get boring after a while.

So now comes personal satellite radio, a medium no longer only for the car. It arrived in the form of the Delphi XM2Go MyFi--the first satellite-radio portable music player. I toted around this little marvel of miniaturization for a month to find out whether it's worth the $300 price tag and the $12.95 monthly usage fee. Built by electronics maker Delphi to receive the XM satellite radio service, the device offers 100 channels devoted to whatever musical genre you can think of, each in all its variations and derivations--rock, pop, hip-hop, country, classical, soul, jazz, Latin, world, vintage songs--with little static and commercial-free. It's like old-school FM on steroids. Add to that handy info on track titles and artists' names, streaming sports scores and stock quotes, as well as a wide selection of audio news, sports, weather and traffic reports, talk, comedy and kids' shows.

Satellite radio signals are broadcast to Earth by powerful transmitters circling in geosynchronous orbit rather than from conventional radio towers on the ground. This means one can hear the same programming on the same station anywhere in the continental U.S., a feature that is especially useful for long-distance auto trips or reception in the rural hinterlands. Until recently, however, pay radio units had been designed for use in vehicles or in stationary locations at home or the office. The Delphi MyFi is one of a new generation of handheld satellite radio receivers--a nifty gadget that represents the first real alternative to the iPod in the ongoing battle for the limited space in your pocket.

Whether the MyFi is truly pocketable is debatable, though. At 4.5 inches tall by 2.8 inches wide by 1.2 inches thick, the seven-ounce unit is a bit bulky to slip easily into your pocket--unless you're wearing painter's pants. It is noticeably heavier and thicker than a 20-gigabyte iPod, for example. In addition, if you put it in your pocket, you would have to attach the clip-on antenna extension wire to get a clear signal. So the MyFi is really much happier strapped to your waist in its belt clip or protective case. And with a five-hour battery lifetime, full-day operation without plugging it into a wall socket is out. In general, however, it did a fine job of delivering quality tunes whenever I took it out jogging or hiking.

Despite the device's chunkiness and limited battery life, its engineers nonetheless did an impressive job of shoehorning all the necessary components into the palmtop gizmo, including a lithium-ion battery, antenna, tuner, memory and display. The monochrome screen is easy to read, and the clickable thumbwheel control permits scrolling through programming and feature menus readily enough. And, like a conventional radio, preprogrammed buttons let you access 30 channels quickly. One cool feature is a built-in transmitter that can be set to relay the satellite radio signal to nearby FM receivers in your house or car.

The MyFi comes well equipped with a full complement of accessories for domestic and automotive use: auxiliary antennas, plug-in power supply, mounting cradles for the home and car console, various utility cables and a useful remote control. The downside to using the attachments is, of course, cable clutter.

The Delphi MyFi delivers clear audio when there is an unobstructed view of the southern sky (where the signal originates) or when it is close to one of the terrestrial repeaters XM has installed in major cities. But reception can be rather spotty when you are mobile and tall buildings or mountains block your line-of-sight downlink. Indoors, more often than not, the signal breaks up when something cuts your invisible tether to the heavens. So inside city buildings, unless you are near a window, reception is intermittent even with the clip-on antenna. At my office, I got good results by attaching the antenna to a venetian-blind slat and tinkering with the skyward aim.

Unfortunately, indoors--at the gym, at work, while shopping, or on planes or subways--is often just where you want to use a portable music machine, and windows are not always accessible. These frequent outages would be a fatal flaw but for the engineers' foresight in equipping the MyFi unit with the ability to digitally record five hours of programming, which you can play back anytime the signal fails.

Use of satellite radio has exploded during the past year. More than 5.4 million subscribers currently pay the $12.95 a month to get service from XM or Sirius, the competing satellite radio providers. Right now XM leads with over four million users, but Sirius is making progress, having signed up 1.4 million customers. Each offers somewhat different (and incompatible) programming, so before you buy I suggest trying out the services through their Web sites (www.xmradio.com; www.sirius.com). If National Public Radio, shock-jock Howard Stern or all Elvis all the time is your thing, you might want to wait until the end of this year, when the first handheld, Sirius-format radio is expected to arrive. XM features NPR refugee Bob Edwards, Major League Baseball, wild men Opie and Anthony, and a premium Playboy channel. Your choice. Note that Tao and Pioneer plan to roll out portable devices for receiving XM radio by year's end.

Satellite radio can lead one to develop an insatiable desire for all kinds of unfamiliar music and talk, in the way shortwave radio opened up new worlds for listeners in the past. I ended up educating myself about exotic music styles I had never much listened to before.

One disappointing aspect of the MyFi is its inability to let you produce customized playlists--you can hop between the songs and shows you have recorded, but it will play those automatically only in the order in which you saved them. Nevertheless, I found the MyFi to be a fun gadget, perhaps attractive enough to make me change my tune and buy one. But personal satellite radio is no slam dunk. The cost of admission is still a bit steep, and I might just wait around for some further miniaturization and enhancement of the technology before I think about plunking down the necessary cash.

Truth is, I'm really holding out for a combination iPod/satellite radio--what some geeks call a wireless iPod, iPod Satellite or SkyPod. This version of the "ultimate personal music player" would let you listen to your own tunes or somebody else's whenever and wherever you wanted. The Net has been rife recently with rumors and reports of discussions of this possibility between the two satellite radio companies, Apple, and the makers of MP3 players. Although this marriage would most likely require overcoming some thorny technical challenges, one can only hope that the coming of the SkyPod is in the stars.