How about this - each team challenges one other team to do something, say, within the View of the New Millennium or some other theme - say "team 1" (the first on the list) challenges the next ("team 2") on the list to, say, make a scene of life in the New Millennium, and "Team 2" challenges "team 3" to maybe do a Sports Scene or something, and 3 challenges 4, and 4 challenges 1?