Pandora

If you haven't tried it I highly recommend checking out Pandora.

It's a free Internet radio station that's unique in that it plays custom 'stations' you create. Simply enter a musician or song you like and it plays like tunes of that genre. Indicate songs you like/dislike and the station amazingly tweaks itself to a whole series of songs you'll love. Very cool. You can setup dozens (I believe 100) stations. Check it out!