I have been recently introduced to Pandora. Pandora is a Flash application which allows you to enter you preferred music taste by artist or song title. It then searched it's database for not only that artist or song but then compiles a "playlist" based of the criteria of that selection. It works like this:

I typed in Nine Inch Nails, it then played Into the void, then Mechanical Animals by Marilyn Manson, then Orgy then Superbeast by Rob Zombie and back to Nine Inch Nails with The Day the World Went Away.

Type in the search and sit back and enjoy the playlist, if you hate something you can guide the system which not only goes to the next song, but helps the AI for the next time.

You get four or five songs, but then you have to create an account, which is free so don't panic. You can then listen until you're blue in the face. Check it out and tell me what you think.