I used pandora for over a year, but after a while you start hearing a lot of the same songs. I now switch back and forth from pandora to slacker.com. Slacker is a pretty good one to hear a few other tunes.
i used pandora a few years ago, but it seems like a lot of work just to listen to music. I used to let it play while i was sleeping sometimes and would wake up because it shuts off if you arent activly using it