Great article by sports columnist Jason Robillard on the main surfaces that you may encounter while running. One surface he mentions is grass, which was also my initial top choice because it was easy to find and seemed to be soft enough for my initial barefoot adventures. But I later realized that grass does not train your feet to run barefoot well – rather, it is a little too soft, and often dirty, especially after a rain. Sand I have found and as Jason also agrees, is a better surface. Read more at http://triathlete-europe.competitor.com/2011/03/30/barefoot-running-tackle-surface.