William Bouguereau's paintings have alot of barefooting people: http://www.artrenewal.org/asp/database/art.asp?aid=7&page=1
Love Bouguereau's paintings, and yes his subject are barefoot almost exclusively, and I think that he probably paints some of the most realistic feet of any artist - this was a man who had a mastery of the foot's anatomy - and that's not easy (if you've ever tried to paint or draw feet, you'll know what I mean).
