Check it out: http://www.audioscrobbler.com
D/l a plugin for your player, sign in, and it keeps track of what you listen to. Mix in a huge database of other people, and you've got tops charts, "people who listen to (insert band here) also listen to (insert a list of fifty bands here)", and recommendations for (new?) music based on what you listen to.
Very cool. And free, too.
P.S. - We need new activity, dammit.
P.P.S. - I have need of new industrial/etc. I lurve teh VNV Nation, but I need new! Any rec's?
P.P.P.S. - WTF is up with allmusic.com?
P^4.S. - Trance DJ recommendation: Ayla. Fan-fucking-tastic.