Is it possible to synchonize my iPod with iTunes on one computer and drag-drop ad-hoc files on another?
I know it was possible with older iPods, not sure about touches though. If you have it jailbroken, you can SSH into the device and store your files that way. You have to have WiFi access in both locations though. That's the simplest way I can think of, sadly lol. 

Here's how to jailbreak. And here's how to SSH. Other SSH info.

Hope this helps!

-Thomas