If you use iTunes streaming, you'll know how annoying it is that you can't download other user's tracks. Get It Together is a pretty simple Java app that solves this problem. If you've got two computers and you need to move music around, it's a great tool in a pinch. It works through Bonjour and DAAP, so there's absolutely no setup. It'll even work on Linux!
And the best part? Glazed Lists is inside.