Actually the coolest part is not audioscrobbler, but last.fm. It sets up a custom internet radio station for you that plays songs from your neighbors' collections. If you have an audioscrobbler account you already have a last.fm account. I listen to it almost exclusivly, has gotten me into a lot of cool bands I wouldn't have ever heard of otherwise.
My account
Edit: Though now it seems both last.fm and audioscrobbler.com are down. Anyone know what happened?