There was an article in Wired (might be this month's or last month's) about universities, Dartmouth was the example, that have made wireless access available throughout their campuses.
I was then thinking about the university I work for and its wireless effort. To connect to the network one needs to download a VPN client and use that to hook (airhook?
I thought that was a rather nifty way to sort of side-step the security issues surrounding WiFi. Don't need to worry about weaknesses in WEP and you could in theory leave the network open since you need to a VPN client and corresponding login.
I haven't really tried to push the security limits of the wireless network but I think it's not a bad decision.