do you scrobble? i do. i'm completely addicted. this is "social networking" in a way that i can really appreciate. for those of you that don't know... :
Audioscrobbler builds a profile of your musical taste using a plugin for your media player (Winamp, iTunes, XMMS etc..). Plugins send the name of every song you play to the Audioscrobbler server, which updates your musical profile with the new song. Every person with a plugin has their own page on this site which shows their listening statistics. The system automatically matches you to people with a similar music taste, and generates personalised recommendations.
the best part of audioscrobbler, is that it is incredibly low impact. all you have to do (presuming you've installed one of the "plugins") is listen to music as you normally would. there's no need to constantly login to check for new messages, or otherwise update information - the site silently tracks your habits, and does a lot of the work. on it's own. just by tracking your listening habits, audioscrobbler does a good job of picking your "musical neighbors" and making musical "recommendations". it's interest-based networking without all the hassle.
plus, i love checking to see my "top artists" and "top songs" to see if they line up with what i know my favourites to be. (so far - pretty good). there's also the sister site last.fm where you can get personalized online radio based on your listening preferences.
to top it all off, there's a highly active, and accessible development community. i poked my head in their IRC channel, and found them to be helpful and responsive.
i must say, i'm addicted. checkout my profile. and if you don't already, start scrobbling!