Divide the boys into two or more teams and line up single file.  The first player in line reaches his right hand between his legs and grasps the left hand of the player behind him.  This player does the same with the player behind him, and so on until the line is linked.  The last player lies flat on his back, still holding the hand from the player in front of him.  The line moves backward at a signal from the first player until each player is lying down.  The last player gets up and moves forward, pulling the whole line after him.  The first team back in position wins.