I know, I know, I'm WAY late on this, this was becoming popular months ago, but anyways: Pandora (www.pandora.com) is AWESOME. It's a free Internet radio that automatically picks music you like.

It first asks you for your favorite artist. So I entered Jars of Clay, and here's what it said to me:

"To start things off, here's a track that's musically similar to Jars of Clay called "Free" by Donavon Frankenreiter, that features a subtle use of vocal harmony, mixed acoustic and electric instrumentation, a vocal-centric aesthetic, major key tonality and electric pianos."

Now, how frikkin' cool is that? You can create up to like 100 or 1000 "stations" that all dynamically play music "similar" to whatever you specify, and it reacts to you saying you like or dislike certain songs.