This activity is awesome and inexpensive to have on hand for students. Depending on group size and the length of the pipe, it can be simple or very challenging.
Try to stomp on each other's balloons, while the balloons are tied to their ankles, part of the fun and games
team building games like this are great! one to do is use a bucket and give everyone cups saying they have to transport the bucket of water you are dumping to the other bucket and here is the catch you poor until it is empty slowly and constantly. the team with the most water at the end/most teamwork used wins!