Open Pandora's... Music Genome Project?

OK, this is really cool... pandora.com

Basically, you create customized radio stations by telling the software what kind of music you like and it finds other stuff that is similar (beat, use of vocals, acoustic, electric etc.). You can keep telling it what you like and don't like (ala TiVo) and it continues customizing itself and adjusting to your tastes.

I'm not sure how many songs are in its library, but they seem to be partnered with iTunes so it could be as big as their whole catalog. It also gives you the opportunity to share the radio stations you've created. I don't plan on doing that because I don't see any need to reveal my predilection for 80's hair bands (apparently categorized by its mixed acoustic and electric instrumentation, a vocal-centric aesthetic, extensive vamping, minor key tonality and electric guitar riffs).