Universally adored by music fans, streaming-music service Pandora is sure to be equally adored by iPhone and iPod touch users, who can get in on the action with the nifty Pandora Radio app.

Like its Web-based counterpart (and like Last.fm), Pandora Radio creates custom radio stations based on a selected artist, song, or even classical composer. Left to its own devices, Pandora chooses subsequent songs based on similarities in acoustics, instrumentation, and the like. But you can also give songs a “thumbs up” or “thumbs down” as you listen, thus helping Pandora learn your preferences. (Tapping the thumbs-down icon immediately skips you to the next song and prevents the previous one from playing again.)

The Pandora Radio app lets you bookmark songs and artists, but you can’t revisit those bookmarks within the app itself: They’re available only on the Web. That’s a shame, as it keeps you from accessing artist bios and other goodies. Indeed, the app offers few of the amenities of its Web-based counterpart. It’s still a blast to use, just not as well-rounded as Last.fm. Like that app, Pandora Radio does include a Buy on iTunes option for instant-ownership gratification.

Talk about a no-brainer: If you’re already a Pandora user, give this app an immediate home on your device. If not, do yourself a favor and see what all the fuss is about.