Hide all of the desktop icons on someone's computer and replace the monitor's wallpaper with a screen-shot of their desktop.
Paint a bar of soap completely with clear nail polish so it won't suds up.
Remove the shower head and place a chicken bouillon cube in it, then put the head back on.
Put tape over the optical sensor of someone's mouse.
Put a "Please Use Other Door" sign on the entrance to your office building if it only has one entrance.
Install the Blue Screen of Death screen-saver on someone's computer.
Take a squirt gun into the rest room stall next to someone and shoot little drops over the wall every couple of seconds while pretending to pee.
Hide an alarm clock in someone's bedroom and set it for 3:00 a.m.
Change the coffee in the office coffee maker to decaf.
Place a pair of pants and shoes inside the only toilet stall in a rest room to make it appear someone is using it all day.
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