If you have about 5 minutes in a computer lab alone and they have optical mouses, put a sticky note on the bottom of each mouse over the laser. And if they are the oldschool ball-mouses, take all of the balls and put them somewhere else.
Last year I got my dad with it and it took him 20 minutes to try to figure out how to reinstall the drivers for his mouse(there were none since it is plug-and-play) on the computer.
nah go in your computer lab or library and get a picture of a cracked computer screen and put it in like iphoto or something and make it full screen and unplug the mouse and keyboard so it looks like the computer is fucked