“Single Canadian women traveling alone who don’t want to be hit on by strange men should wear a fake wedding ring and have a photo handy of their imaginary husband, says a travel guide entitled “Her Own Way — A Woman’s Safe-travel Guide,” issued by Foreign Affairs Canada.”
More here from the Toronto Star.
Feminist Philosophers 
And they should say that the husband is a sniper in the Army.
Wear a big crucifix around your neck, carry a Bible and if he approaches, talk about Jesus. It works.
S. Wallerstein, particularly if you’re traveling in the Middle East.
I have a funny feeling this strategy is only going to weed out the more benign approaches, leaving the industrial-grade creeps unaffected.
just tell him you’re a feminist. should scare him off.