A brief fad in the late '70s, barefoot rock climbing, has always intrigued me. Chalk up the hands and feet and go. People in parts of the world where they can't afford shoes have no choice.
I once lead the Arete, 5.6, at Pt Dume (http://www.summitpost.org/mountain/rock/499319/point-dume.html). That wall is often so greasy that sticky shoes don't matter much. It was an interesting experience. I'd say I'd have to really condition my feet before doing that much more.
What have you done?