Check out Pandora.com. I learned about this from Gutterboy Live, a Live Journal. It is a great tool for streaming music. You type in an artist that you like and Pandora builds a station based on that artist and introduces you to new artists with similar music. You can have multiple stations. So far I have Petula Clark Radio (with Burt Bacharach added), Ray Charles Radio, Willie Nelson Radio (with Johnny Cash and Dolly Parton added) and John Coletrane Radio.

The Willie Nelson Radio station has been most interesting because country is not the only genre that Pandora draws upon in choosing songs to play. I've heard Chris Isaak, Tonic, Train, Kelly Clarkson and other non-country musicians.

Pandora is part of the music genome project so it picks songs based on beats per minute, production qualities and other criteria. There is a rating system so if you do not like something that song will not be heard again. If you like something Pandora finds other songs like it.

Unfortunately, it does not do classical or world music. Only available to U.S. listeners.

Go check it out. I'm going to attempt to build a Ravi Shankar station.