What you need:
3 or 4 crazy wild and un-shy kids
A noisy riled up crowd
4 youth leaders to serve as judges
The game starts by selecting you wildest kids, like 3 or 4 of them, and sending them out of the area where they cannot see or hear anything. Set the chair in the middle of the stage. Tell everyone that the kids that just left are going to demonstrate how they go to the bathroom. Meanwhile in the other room, have a leader tell each kid as they are going out that they are doing something else. Send each kid out one at a time and they have thirty seconds to do their thing. What's so funny? Tell the kids that are performing that they are, for instance, riding a roller coaster, or a motorcycle, or even that they are in a rodeo. It is funny because neither group of kids has a clue what the other is doing. It is a real funny one and really gets kids acquainted with one another.
The judges rate who did the best, by making the crowd laugh the most. That person wins.
The game works well with team activities too. You can have a rep. from each team do it. Then it provides a time for unity as well.