Oh... I misread that at first and thought you were saying we should broadcast that we are American, and my first reaction was, "Why would we want to do that?"

Now that's out of the way, one should wear socks that match your outfit to some degree. I'm not sure how that goes with jeans, but with most outfits, one should match. Since I don't wear pants anyway, but skirts, I generally wear some kind of hose/stockings. Well, unless I'm wearing sandals, in which case one definitely doesn't wear white socks, but goes barelegged if they are casual; if formal, it might be appropriate for women, at least, to wear hose. Come to think of it, I can't think of "formal" sandals for men....

Of course, I'm American, so what would I know?