Ladders

Split the kids into boys and girls.
Have each boy, and each girl, find a partner in their group, and have them sit down and put the soles of their feet together.
Have each partner set leave about a foot between them and the next partner set.
Number each set of partners (you should make sure to have the same number of partner sets in each group).
When you call out a number, the two sets of partners with that number must jump up, run down the ladder (over the legs of the partners in their line), run back to the beginning, over the remaining legs, and get back to their spot before the other group of 2 does.
First group of 2 back wins a point for their group.
Play for a specified time limit, or up to a specific point total.