I really enjoyed that book (Born to Run). I read it as I was training for a marathon, and it was a big motivational boost when I was getting worn out.
It would seem like common sense that we evolved barefoot, and should therefore run best that way, but it's hard to break the shoe habit. I've gone for a few runs barefoot, but since there aren't any good grassy areas in my neighborhood to run on (well, I could trample my neighbors' lawns, but I don't think they'd appreciate it) it was tough and I never made it too far.
I need to try it again and see if I can work my way up to running a barefoot 5K this summer.