Mediamaster has an interesting service to save your music online.

  1. Sign-up and upload all your music. It’s stored and backed up
  2. Listen to your music collection anywhere on any computer using just your webbrowser
  3. Using the MediaMaster widget you can post your collection, playlists and radio stations to your blog

So far, there’s no limit, it’s free and totally legal.

Here’s a screencast of it: