Create groups of 6 to 10 people and provide each team with a "Magic Carpet" (a tarp measuring 5 feet x 5 feet).
The team stands on top of their tarp and is then asked to "flip" the tarp over without anyone touching the ground.
This is a teambuilding game you can lead with small groups or large groups (500+ people). If the groups collaborate this teambuilding game becomes much easier. You'll see an example of collaboration in the video clip https://www.youtube.com/watch?v=mbsdg7TGzUk