Besides some bitchy piece of hardware, I don't see any reason to NOT use DHCP.
I've personally found 3 wireless networks around the school. I know one is the "portable computer lab" (laptops with wifi) and a teacher runs another one (kindly hooked up net access - unfiltered incidently for a couple of days) but can't seem to find the 3rd one, the signal is too weak.
I really want to go wardriving with this iBook before I need to bring it back to the school (ie whenver someone else needs it)