Wifi has become an expected standard at industry conferences. Steve Gillmor take the point further that access should actually work and we should demand open access, power and cell phone coverage from organizers before attending.
He mentions how Macs outperform in these environments, but what he doesn't mention is the lesser known fact that the proliferation of Macs has become perhaps the biggest problem at events. When people create and share networks from their Powerbooks, it causes collisions that interfere with everyone's access. At PC Forum there were six people doing this at one point for no reason other than ignorance.
So here's a lazyweb: The Sharing Suppressor identifies Powerbooks who are sharing networks and bluejacks to bombard them with messages until they stop polluting the commons.
UPDATE: A related concept (Jeremy, give this trash talking a purpose!)