We're all looking for ways to better engage attendees—might this be one of them? Possibly, depending on your group. Check out the results of New York Times media columnist David Carr's experiment at SXSW, which entailed gathering some geeks to tell insider geeky jokes. Cracked me up, anyway. (Warning, there is one expletive and mild potty humor.)
I could see an organization sending out a request ahead of time for people to videotape themselves telling their favorite insider joke, compiling them, and showing the results during a general session or luncheon as an icebreaker kind of thing. You could even turn it into a contest, but I kind of like just putting it out there. Others might not get the jokes, but that's kind of the point, isn't it?