I'M AT BLOGGERCON at Harvard Law School where I just did a panel on weblogs and journalism with Scott Rosenberg, Josh Marshall, and Ed Cone. There's wi-fi in this classroom, but it doesn't work very well: it's intermittent and painfully slow, and my posts keep getting lost. People have to be individually logged in with MAC addresses, and then it still doesn't work.
It's the best argument for truly open wi-fi I've experienced -- except for the wi-fi at my hotel, which is free but requires a login, and which kept dumping me back to the login screen every second or third time I would try to follow a link.
The access-control systems on wi-fi seem to cause most of the problems.