I was just shown this by a co-worker that heard about it on the Inside The Net podcast. (Podcasting is a whole different topic that I may blog about later...)
I've recently started getting back into music listening with all the latest iPod craze and whatnot.
Anyway, Pandora is a great place to learn about new and different music that you might want to add to your collection. You start by entering a song title or artist and what follows are audio streams from a huge library that try to match music to your taste. I'm still playing with the technology but so far I'm pretty impressed and have discovered (and re-discovered) lots of great music so far. Right now the service is free but they are planning on introducing more advertising space to offset costs. You can pay a subscription to avoid the advertising. Check it out and let me know what you think.