It might be easier to just bring some cheap wireless router and plug it into their network. It might make their IT guys irritated, but would solve your problem.
Haha, IT guys…lawl, that’s funny…my school is…just…haha, I doubt we even have a room for the IT guys, now…on my quest find a micro wireless box. Haha, maybe I’ll duct tape it to the back of my iPod Touch…
Maybe something like this that you can connect to your desktop computer and share internet to the wireless. Then use your iPod to connect to this wireless signal.