I haven't really dug deep into it yet, but it looks pretty neat.

http://www.mp3tunes.com/

You can backup your entire music library to it (nice way to protect from the loss of your music) and stream from it to any computer connected to the internet. Looks like you can even stream to Tivo and some cell phones. Works with iTunes.

There's a limited free version, but even the full baby is not that expensive.

This actually isn't new. I've been using their service to backup my music collection for about a year now. It works pretty well, although their upload software is extremely slow and kind of flakey.

What is new is that they have significantly increased what they offer with their free service.

-Jeff