Alarming Alarm Clock
Set someone's alarm clock an hour early. Or set a bunch of clocks to go off at the same time, and hide them around the room for a noisy wake-up call.
Mean Money
Tape a dollar or a quarter to the floor in a high-traffic area, and watch the parade of clowns bend down and unsuccessfully try to pick it up.
Puzzling Message
Confuse callers by leaving the following outgoing message on your answering machine: "Hello? [pause] Hello? [pause] Is anyone there? [pause] April Fools'!"
Uninviting Bed
This old classic never gets old: Short-sheet a bed by tucking in both ends of the top sheet at the head of the bed. When the fool crawls in, her feet will stop short.
Unidentifiable Object
Insert a raisin into a tube of toothpaste. The unsuspecting person who squeezes it will be dismayed by what comes out onto his toothbrush.
Infested Ice Cubes
Pop some plastic ice cubes (the ones with toy flies or ants inside) into your guests' drinks, and watch their expressions go from thirst to horror.
