i grew up in a place where i used to go everywhere in sandals and play sports i.e. soccer barefoot. i had my share of incidents like stepping on a broken glass, it didnt hurt but the cut was deep enough i could see thick red blood (like jelly) coming out of my foot.. anyways, now i've started running and could not imagine how i would run barefoot as when you run, you cover a wide range of areas, there could have been broken glasses laying around on the streets, etc.. you'd never know.. and i enjoy having some sort of foam to absorb the shock on your feet when running.. so unless you're running on a specified running track like the ones in the olympics stadiums (although this doesn't mean that you wouldnt get injuries/into incidents), i would never run barefoot..