Another practical joke under the guise of a co-ordination test is the following. Ask your victim to take a quarter and place it on a piece of paper. Then ask him to take a pencil, and without removing his finger off the quarter, to draw a circle around the quarter. Have him repeat the same exercise with each of his fingers pressing on top of the quarter. Afterwards, have him pick up the quarter and rub it along the bridge of his nose. It'll then be really funny to watch him walk around with a black line on his face.©OFFICEJOKES.NET

I also have heard of a practical joke that can be done to a person while he/she is sleeping. If the person's hand is dipped in warm water, this causes a subconscious relaxation of the bladder and causes the person to wet his/her bed. I have never tried this, nor have I seen it tried, but I've heard it from quite a few people. Has anyone out there ever tried it?