Write a message on an upside-down paper cup that alludes to something horrible being trapped under it.
Leave it on a coworker's desk or in a conference room.
1476
1
Install the Blue Screen of Death screen-saver on someone's computer.
828
3
Put tape over the optical sensor of someone's mouse.
863
1
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.
768
0
Change the coffee in the office coffee maker to decaf.