I've often pointed to stuff in the past about the benefits of being barefoot (although I never write as well as mc on this or any topic)
Here is an extract of a good piece from the co-author of the Paleo Diet for Athlete's, Joe Friel:
I wish it was so easy as to say that we should all just run barefoot. Had we grown up like Kenyan kids - barefoot and running to school every day - we wouldn't need heavy-duty shoes at all. Our feet and legs would be strong and our technique would be excellent. Unfortunately, that simply isn't the case. We grow up wearing shoes as soon as the parents can dress the baby. I'm afraid the feet of most of us are not well-conditioned. But we can do something about that.
I think it might help if you got out of your shoes during the day whenever you can. I'm not talking about running shoes here, but rather your 'street' shoes. Taking them off around the house is a minimal but first step in strengthening your feet. Athletes who do this can progress to doing what I call 'barefoot strides' a couple of times a week. I start them off with doing 5-6 x 20 second sprints on a clean, grassy surface (with walk-back recoveries). If not ready for barefoot running try using a lightweight racing flat, Nike Frees, beach water shoes or Vibrams. The idea is to gradually do more walking and running with little or no footwear.