First, a little history, I've always been a proponent of lighter footwear. I really focused on it during 2007 while I was training for a speed record attempt on the John Muir Trail. The logical extension of lighter shoes is no shoes. That didn't seem reasonable for what I was doing but it stuck with me as something scary but interesting.
The next post I'll describe how I started but I continue to run barefoot because of the sensation. There is an extremely visceral feeling running with nothing on your feet. I guess it's similar to working with your hands to build something, instead of just typing on the computer. I don't even run with music anymore. It still feels weird leaving the house with no shoes. I think it would feel more normal wearing shoes but no cloths.
Ultimately, it gets me out running more and that's the most useful part.