This Activity is meant for Scout scouts.
Decide for yourself if it is appropriate for your younger scouts or not.

I just invented this for a patrol of new scouts at their first patrol meeting as a way to get them used to the sign. But, they kept playing it for about 15 minutes.

Have all scouts sit in a circle facing inward.
One scout is chose as 'IT'. He stands up as everyone else in the circle closes their eyes.
The scout walks once around the outside of the circle and taps one scout on the back.
When he gets back to his spot, he sits down and says, "Heads Up!".
Everyone starts talking, making lots of noise, and keeping their eyes watching everyone else in the group.
The scout that was tapped makes the Scout Sign whenever he wants.
The first scout to see the sign, put his up, and stop talking wins.
The winner gets to walk the circle and tap the next person.