Number magnets to keep track of kids you allow to leave the room. Use a cookie sheet with glass stones glued to scrapbook paper and a magnet. then trim in fun duct tape! (The cookie sheet magnet board is pretty sweet for multiple different crafts.
I thought the idea of incremental punishment is good, gradually prolonging the loss of recess time gives teachers and students room to work and improve before giving them a harsh consequence for misbehaving based on the level of misbehavior.