Beware of a man with a gleam in his eyes - it may just be the sun shining through the hole in his head. (Women's washroom graffiti.)
The best way to a man's heart is to saw his breastplate open. (Graffiti in a women's washroom.)
A woman's rule of thumb: If it has tyres or testicles, you're going to have trouble with it. (Sign in a women's washroom. In the US tyres would be tires.)