Hey, not suggesting that you were going to add your personal opinion, just wanted to back up the previous posters - that it is done, and done quite often. I can't even speculate as to the origin, Docksiders are worn without socks primarily because, when used for their original purpose (i.e. sailing) one wouldn't want to wear socks - you're just going to get them wet) Loafers probably were just a continuation of that trend. I'd like to find out for sure, and find some sources for that. I agree it is definitely a US trend, I probably would find it strange, if it hadn't been a tradition since I was very young. If you want to read more about the eccentricities of American dress (at-least the conservative / preppy kind) I'd recommend flipping through The Preppy Handbook by Lisa Birnbach, originally written as quite tounge-in-cheek, it has been taken seriously partially because although a parody, it's quite true i most respects.