Personal Radio?

I've long been a fan of Audioscrobbler and a user there, but I've been waiting for them to do cool stuff with the data.

I don't know exactly what the relationship is with audioscrobbler, but Last.FM appears to be everyone's audioscrobbler data (like mine), but with mp3 streaming of the music. I just tried it out and heard my own collection streaming back at me, as a virtual radio station. It will even let me hear all my friends' music in streaming form.

Something makes me think this can't possibly be legal or last for any length of time, but it is a cool use of Audioscrobbler's data.

update: Since I posted this I've learned that audioscrobbler and are working together off the same data, share the same programming teams, and are housed in the same building. I've also heard that unlike the case in the US, under UK law, the site is legit and legal the licenses the company has are a-ok on internet streaming, which is great to hear. I'd hate to see either useful, cool service go the way of the original napster dodo.