A decade ago, I had the very great pleasure of having Mary Roach follow me around for a day while I ran an experiment. (At the time, I was investigating the mechanical behavior of the mammalian baculum. She wrote about it later). Since then, she's become the author of three books: Stiff, Spook, and (most recently) Bonk. Here's a talk she gave at the 2009 TED conference based on stuff she learned for her new book. Just watch.