Paint a bar of soap completely with clear nail polish so it won't suds up.

 618

1  

Hide all of the desktop icons on someone's computer and replace the monitor's wallpaper with a screen-shot of their desktop.

 719

0  

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.

 619

1  

Remove the shower head and place a chicken bouillon cube in it, then put the head back on.

 580

1  

Install the Blue Screen of Death screen-saver on someone's computer.

 683

3