electricity

Everyone stands in one big circle and holds hand. Someone starts the game by making the first "charge" - he squeezes the hand of the person next to him. As soon as that person feels that his hand is squeezed, he must squeeze his neighbour's hand. That way the charge starts going arund the circle. The goal is to make it go around as fast as possible.
To make the game more difficult you can make two charges go in different directions.