I stumbled across Last.fm yesterday during one of my “I’m incredibly bored, lets see if there is anything on the internet” periods. Last.fm used to be called Audioscrobbler, which is a service I had heard about before. Basically what you do is create an account, then install a plugin for your favorite music player. The site tracks every song that you listen to, then after you listen to about 300 or so it groups you up with other people who have similar interests and it recomments songs based on what they like.
So far I’ve probably listened to 100 songs. Here is my page. Its got a list of all the songs I’ve listened to, and how many times. If you create an Last.fm account be sure to add me to your friends list… or else.