Windows and Mac OS X only: Freeware program iPod -> Folder allows users a super-simple way to do a full backup of their iPod on any Mac or Windows computer.
We've actually posted a few methods for backing up your iPod in the past, but iPod -> Folder is a nice standout both for its simplicity and it's Windows and Mac versions. The downside is that iPod -> Folder doesn't allow you to selectively backup music, so it's an all-or-nothing affair. That said, this is a great little app to download and stick on your iPod so you can easily "back up" your music at any computer. Thanks Rory!