I've heard about this one before, but I'm downloading an episode now.
The one thing I hate about QI is that I've already seen it all and there aren't any more episodes.
Edit: That was great. It totally scratched the QI itch. Among many other tidbits, I now know how leech treatments were discovered, that there's a specific frequency that is arousing for badgers and sets off car alarms, and that in one year, over 700 American students were arrested for owning pagers.
Edit: Holy shit. The author of Goodnight Moon literally died from an overly-enthusiastic "can-can kick". She did it to prove she was feeling fine... (ironically) but she dislodged a blood clot that instantly killed her.