Whenever someone is annoying me in a public place, when I walk by them in the halls or the streets, I quickly glance at them and proclaim aloud: "Why are there so many ugly girls/women here? Gross!" Don't look back. Don't hesitate. Keep your stride in a rhythm.

It works like a charm. Those girls will spend the rest of the day mulling over who you were referring to in that moment.

I use it on obnoxious drunk Madonnas all of the time. You know the types - the ones who sexually assault men but get away with it 'cause they're overtly attractive. This technique ALWAYS works. Better yet? It's an indirect relationship. The uglier she perceives you, the more the insult hurts her.