Gnoosic - Even if you don't know what you are looking for - gnod will find it.
Musicroamer - A visual Pandora for discovering new music
cmd.fm - Command-line radio for geeks
TasteDive - TasteDive recommends similar music (musicians, bands), movies, TV shows, books, authors and games, based on what you like.
TuneIn Radio - With TuneIn Radio Mobile, your mobile device becomes the radio.
LivePlasma - Discovery engine map for books, music, and movies