The BBC Sound Index

Wow, the BBC Sound Index is cool. It trawls through social music sites to get a top 1000 chart of artists and tracks.

"The Sound Index is a massive index of the hottest bands and tracks that are being talked about on the internet right now.

Every six hours the Sound Index crawls some of the biggest music sites on the internet - Bebo, MySpace, Last.FM, iTunes, Google and YouTube - to find out what people are writing about, listening to, watching, downloading and logging on to. It then counts and analyses this data to make an instant list of the most popular 1000 artists and tracks on the web. The more blog mentions, comments, plays, downloads and profile views an artist or track has, the higher up the Sound Index they are. So, the Sound Index is a music buzz index controlled entirely by the public."

ITunes and YouTube seems to dominate, but you can make your own chart, picking the services you like.