How many of you use LastFM, whether as an artist or as a listener?

If you've got an active music project, you've probably already got an automatically generated profile up on the site, by virtue of listeners having listened to one or more of your tracks. Go check.

You can edit your information, upload tracks with the usual stream/download controls and, best of all you get paid direct royalties with quarterly reports for what's been listened to. Beat that, Myspace.

As a listener, not only can you track and share what you listen to, but the site will create a radio stream based on what you listen to, one for stuff you already like, one for stuff you'd probably like. And it does a good job. It applies that same sort of 'youd probably like this' logic to meeting other users, whose profiles you can then pillage for more music, etc.

This all works from a process they call Scrobbling, which is basically the export of their lean little multiplatform program that pulls the new plays from your media player software (iTunes, etc) and adds it to your profile database on the site. http://www.last.fm/download/
Source code is available. How cool is that.

Been a user on LastFM for about a year now.
Very clever, highly recommended. =]