I found this lecture/Q&A session from the author of born to run. It's kind of long at an hour but it gets really interesting, especially when he talks about proper running techniques and humans pack hunting by running prey to death.
definitly worth watching if you have the time and are interested in the barefoot running craze and ultra distances.
also on another note he talks about a chick named Jenn Shelton who is a badass ultra runner. The first race she ever ran was like fifty miles, she thinks that marathons are so silly for runners that to prove her point she's run them in string bikini's and drank beer along the way and still smoked men's times.
http://barefoot-training.blogspot.co...ints-from.html