A friend just turned me on to the Music Genome Project at http://www.pandora.com/. Type in a song or artist you enjoy, and it begins playing other songs that share various similar qualities and you let it know if you like the song or not, and it begins figuring out what your tastes are and suggests other music based on your feedback. Suggestions are not based on sales or marketing categories--they're based on the actual qualities of the songs. What a relief!