How to Penny a Door Shut

You won't think pennies are worthless if you've ever used them for this.


Lock Someone In A Room Without A Key

I knew some guys who combined this trick with a vacuum cleaner that turned on when you plugged it in. At 3am, They dropped the vacuum in the room of a guy that was sleeping and ran the cord out the door. After pennying the door shut, they plugged in the vacuum and let the hilarity ensue.