This is probably old news to most of you, but I just chanced across Pandora today and I was quite blown away by it. Well, it did happen to be a time when I was rather bored of the current songs on my playlist (I still love 'The Artist in the Ambulance' by Thrice and 'Slow Motion' by Third Eye Blind, probably played them a 2^20 times on my iPod), but it is still pretty awesome even then.
So what is Pandora? (You'll want to skip this post if this is old news to you.) With Pandora, you enter a few songs or artists that you like, and it plays similar songs that it thinks you'd also like to listen to. Nothing really special, except that the results returned are based on some Music Genome Project and it seems to do pretty well in playing great songs I like from bands that I'd never heard of before. It has a Flash interface through which you basically do everything, and it will stream and playback songs, and you can have different "stations" for different types of music/artists you'd like Pandora to match against (so I can have, say, one station that plays songs like "Stare at the Sun" by Thrice, Weezer-like songs, and heck, even throw in a little Bowling For Soup for a little pop punk flavor).
As it plays each song, you can give it a thumbs up by indicating you like it, or if you indicate your distaste, it'll skip to the next song. It uses this to fine tune the type of songs it plays for you so it learns more about your tastes the more you use it. In practice, I haven't used it long enough to observe any noticeable improvement in the selection of songs it plays for me, but then I'm a mere 1-day old user. That said, I've liked roughly 4 out of every 5 songs Pandora has played for me - that's pretty awesome.
Anyhow, the service is free and sponsored by ads, but you can also sign up for the paid service to remove the ads (that's the only difference between the free and paid versions, for now). There are convenient links for you to buy any songs that caught your fancy from Amazon.com or Apple. Apple really needs to set up an iTunes music store here soon, rather than late next year as was mentioned in the papers today - I'd have bought some tunes already if not for that.
So check Pandora out if you haven't already or just read about it in passing - if you love your music and are finding a shortage of new tunes to hum or sing along to, this could be your answer to unravelling new favorite artists and songs.