Use a pin to make a few small holes in a plastic disposable cup. The holes should be near the top, just below the rim. Offer a drink to the victim and watch while the liquid dribbles out onto their shirt when they take a drink.

Add some yellow food coloring to water, and sprinkle it liberally all over the toilet seat and on the floor around the toilet.

Steal your victim's cell phone and tape it under a desk or chair, or hide it somewhere they'll never find it. Then start calling them while keeping your phone hidden.

Find a small picture of a a funny creature ( monkey , donkey , baboon, etc) and use a glue stick to place it over the photo on victim's driver's license. Then send them out for beer, or have some better excuse to send them somewhere where they need to show their ID.

Put a small amount of paint or ink on your finger. Go up to your victim and pretend to notice a "mark" on the victim's face. Tell the victim that you'll rub it off. Instead, actually place a mark ON their face. Act like you got the mark off and walk away.

Announce about the engagement of your friend on Facebook and tag him!