I'm not trying to be cute here, but since we're talking potty talk;
In the restroom at my school it amuses me to draw a very detailed, realistic, and nasty looking sack directly under the coat hook on the inside of the door to the stall making it appear that there is an erect stainless steel thingy kindly offering to hang your jacket whilst you relieve yourself. The janitors repeatedly scrub it away, but they find it curiously returns quite often.
Anyway, I always thought it was stupid how when another male is using the urinal the rest have to occupy a stall to tinkle. People can be ridiculously squeamish.
So in saying that, I'm a 'wall fountain-usin' man'.