Source: The New Games Book
Create (and attempt to untangle) a human knot by holding hands with other players. To form the knot, stand in a circle, shoulder-to-shoulder, and place your hands in the centre. Now everybody grab a couple of hands. If you ever want to get out of this, make sure that no one holds both hands with the same person or holds the hand of a person right next to them.
Now try to untangle the knot without letting go of anyone's hand.