BarCamp? What's that? No... you won't be learning how to make martinis. Check out the site. Participate. From the sidebar on the site:

BarCamp is an ad-hoc gathering born from the desire for people to share and learn in an open environment. It is an intense event with discussions, demos, and interaction from attendees.

The first meeting is Friday Sept. 29th, 2006 at UW, but it's not an event specific to the University.