New resource at NCTM's Illuminations, an activity that parallels proof structure with the structure of jokes.
But the main reason for this post is to spread the news of their 2010 Illuminations institute. A group of teachers will come together to write new and interesting lessons. Only open to K-12 teachers, so I'm out. But you could be in! Find out more. There's a stipend...
From the always entertaining sometimes profane xkcd.
"Well, the telling of jokes is an art of its own, and it always rises from some emotional threat. The best jokes are dangerous, and dangerous because they are in some way truthful." - Kurt Vonnegut
"The love of truth lies at the root of much humor." - Robertson Davies