I found a good, free program via Google search. I think it was called CopyTrans (I could be wrong about the name). You can keep a copy on your device and then run it from there, (when linked to a computer as an external drive - I found easy instructions via Google), so you can transfer songs to/from any computer without having to install the program. It also has sync function.

Anyway, there are a few decent free programs (don't bother with trial versions of commercial software) that will let you do away with iTunes. However, you should keep iT on your device in case you need any firmware updates from Apple.