LastFm

Social Software for Audio listening

http://www.last.fm/

<http://www.last.fm/user/Bill Seitz>

Jun'2007: bought by CBS.

Has ITunes "auto-scrobbler" plug-in to record what you listen to.

• but doesn't seem to import existing ratings from ITunes

Doesn't seem to have good way to find your friends who already have LastFm accounts. Or maybe nobody in my GMail address book is a member...