Westword has a roundup of odd 1970s classroom posters that have been severed from their original captions. It's hard to imagine what lesson they were meant to convey initially, but Westword's made some educated guesses.
I write books. My latest is a YA science fiction novel called Homeland (it's the sequel to Little Brother). More books: Rapture of the Nerds (a novel, with Charlie Stross); With a Little Help (short stories); and The Great Big Beautiful Tomorrow (novella and nonfic). I speak all over the place and I tweet and tumble, too.