Love Last.fm? You may like its eponymous iPhone app. Not familiar with the service? Do yourself a favor and try AOL Radio or Pandora instead. It’s not that the app is bad, per se, it’s just confusing and inconsistent, especially compared with the competition.

Last.fm creates custom radio stations based on your favorite artists. So if you like, say, Brendan Benson, just type in his name and you’ll get a station featuring him and similar artists. As you listen, you can “love” a song or ban it, the idea being to help Last.fm learn what you like and don’t like—and choose songs accordingly.

The iPhone app (which also works with the iPod touch) requires a Last.fm account—creating one is free if you haven’t already. Run the program, tap “Start a new station,” and enter an artist, tag, or user name. While you’re listening, you’ll see familiar options like love, ban, skip, and share (which lets you e-mail a track link to anyone in your address book), along with a Buy on iTunes button.  The app also provides artists bios, a list of similar artists (any of which you can tap to create a new station), and even a roster of upcoming shows for the selected artist. Neat.

Not so neat: The app obscures album art by displaying song info right on top of it. Even more annoying, pressing the Stop button bounces you out of the now-playing page, back to the station list. We also had trouble figuring out a few of the main-menu options, like Neighbour Radio, which isn’t explained anywhere—not even on the Last.fm site.

Playback wasn’t always smooth; we occasionally got connection-error messages and choppy audio. Ultimately, Last.fm is worth a try if you’re a fan of the service. But you’ll have an easier time with Pandora and a richer experience with AOL Radio.