Make your own radio station on the net

There are a couple of great sites that can help to find new music. First up there's Pandora that creates a radio station based on an artist or song name you choose. It works out songs based on the characteristics of that first choice, and can then be trained by giving the thumbs-up or down for particular tracks. The other site is last.fm. This seems to use various methods to choose similar songs, like accepting cash from record companies (just like a proper radio station then). It also plugs into your media player of choice which is probably pretty handy, although I've not checked this out yet. It's also a bit more of a community since you can tag songs and join groups and all that kind of stuff.