Im listening to LAST.FM for a few days now and started building my profile. Like openbc, flickr or del.icio.us this service is what everybody calls now social software. It is a new approach to music in the net, as Michael Breidenbrücker, Founder of LAST.FM, explains in this video.
The core of the service is again – collaborative filtering of content, showing music in its social context. It connects people who love the same music. I realy enjoy it. Check it out.