I went to FOO camp two weekends ago, and ended up having a pretty good time. I was worried, at first, that my interests and skills (computer graphics, numerical optimization, and to a less accomplished degree, robotic/new media art) would be irrelevant in the face of the various blog people and "future of SOAP" technical discussions. However, the other attendees were by and large interesting people with wide-ranging minds, and we found a lot of common ground.
Although the people there were sharp and fun to talk to, the conference sessions themselves ended up being a bit weak. They suffered from a certain lack of organization, not only in timing and place, but also in focus. About a third of the talks I went to started out interesting, but kind of wandered off into irrelevent territory. The best example of this being the "Future of Email" talk, which started out with some interesting input on "email as a message" vs. "email as instigating a validated channel of communcation", and degenerated into a room of people listlessly watching some guy in a cloak doing nslookups on his laptop. However, I think disorganization is the price you pay for an ad hoc conference and, as disorganization goes, FOO wasn't bad at all.
Not to end on a negative note, I had some very good times chatting with Tim Anderson, who co-founded Z Corporation, a 3D printer company, MIT media lab art freaks Cameron Marlow and Jonah Peretti, as well as my friends Joshua Schachter and Maciej Ceglowski.