I just got done reading a fascinating book Born to Run by Christopher McDougall. It is a book that describes an amazing adventure that stemmed from one question, "Why does my foot hurt?" The author has had consistent running related injuries from only light running and is told by doctors that running is the cause of his injuries.
He sets out to find whether or not humans were really made to run or not. Along the why he encounters some of the top ultra runners in the sport today, including Scott Jurek, and the Tarahumara Indians of Mexico. The Tarahumara are an tribe of people know for the peaceful but harsh existence in the Copper Canyons of Mexico and for their ability to run long distances at great speed.
The author tells of a great race pitting some of today modern ultra runners against the top runners of the Tarahumara tribe. A race that allow us really pit modern science against the warriors of the past. McDougall as make a pretty strong case that humans were made to run and the "problem" is our shoes not our inability as a species. It is somewhere in between an adventure tail, documentary, science experiment and spiritual realization. He make a lot of strong points for ditching those over engineered and over priced running shoes.
I strongly recommend this book for any runner, but the book also does a great job at captivating you with a great story while getting the authors point across.