MP3tunes have launched their Sideload service, which allows you to paste in URLs of music files found on the web. Sideload saves the URLs and allows you to stream the files or sync them to your PC. There are about 30,000 tracks on the site but there seem to be many duplicates right now. There is a lot of obviously illicit stuff available there, like Beatles and Zeppelin tracks, but since Sideload doesn't store the music and they promise to respect take-down notices they hope they are safe from litigation.