Cool article in Wired today about the benefits of running barefoot. The article says it much better than I can, but there is a small, but steady base of support (no pun intended) for ditching the supported running shoes and allowing the foot to go through it’s natural stride.
If you are thinking about making the switch, do it slowly. Adapting your feet takes time, just like making any other training adaptation.

I'm sure there is a caveman drawing somewhere in the world demonstrating the virtues of orthotic inserts. The guy who drew it probably became a mammoth-meal, while his friends who took the "run like hell" approach lived to fight another day.
Some people swear by it. http://runningbarefoot.org/
Why stop at bare feet?? http://www.fraternitysnoqualmie.com/BBFR.htmlI did this a couple of years ago and it was a blast, wish I was healthy enough this year to do it.
As a barefoot runner for nearly 8 years I can attest to the benefits of running or walking shoeless.