Last.FM : social-ism for audiophiles
(I must be ill or something, 3 posts the same day :)
I discovered few weeks ago last.fm, it's a great shot! it simply keeps track of what music you listen, make some stats and trove some neighbours for you, having similar music tastes. This process help me to discover new music. And all of this for free, even though you can upgrade your account and pay few bucks to have some more goodies.
From the developer point of view, it's really well designed with its WS API, writting an AudioScrobbler plugin for ResPyre was quite easy :-) So, if you have a look on the left side of this blog, you'll see the last tracks i've listened to.