Another great time-waster waiting for an activity to start.

All scouts form a larger circle, placing the palms of their two hands together and bowing to the group to indicate they are ready.
One scout starts the game by raising his palms-together hands up and chopping them down to point at another player, and yelling, "Ha!"

The scout pointed at raises his palms-together hands up, and yells, "Ha!"
The two scouts on his immediate left and right must chop their palms-together hands horizontally in towards that scout, and yell, "Ha!"
The scout between the two still has his hands up, so he chops them down to point at someone else and yells, "Ha!"
All this is done in a rhythm, over and over, so it sounds like "Ha - Ha - Ha - Ha - Ha - ...". If someone reacts too slowly or misses his role, he must step out of the circle and a new round starts with a smaller circle.