Paint a bar of soap completely with clear nail polish so it won't suds up.
Hide all of the desktop icons on someone's computer and replace the monitor's wallpaper with a screen-shot of their desktop.
Put tape over the optical sensor of someone's mouse.
Remove the shower head and place a chicken bouillon cube in it, then put the head back on.
Put a "Please Use Other Door" sign on the entrance to your office building if it only has one entrance.
Change the coffee in the office coffee maker to decaf.
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.
Install the Blue Screen of Death screen-saver on someone's computer.
Hide an alarm clock in someone's bedroom and set it for 3:00 a.m.
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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