Audioscrobbler is a new Web service that recommends music based on what you're listening to with WinAMP or XMMS. Song information is submitted via HTTP GET/POST requests, so it ought to be easy to extend the service to support other players.
While I'm writing a book, I'll be feeding Audioscrobbler a lot of one-step-removed elevator music. It'll be interesting to see what the service recommends, since most of the 600 listeners appear to be considerably less mellow. Via Boing Boing.