One person lays on his back with his legs tucked into his chest and his arms around his legs. The other person jumps around the trampoline trying to the the popcorn to "pop." The popcorn is "popped" when the person can't hold his legs into his chest any longer because of the bouncing. Switch positions after the popcorn is "popped."
One person holds on to one end of a jump rope and lays the rest flat on top of the trampoline. The person holding on to the rope begins to move it back and forth like a snake across the trampoline. The other player tries to avoid the "snake," but if she runs into it, she is out and has to switch places with the jump rope holder.
Test your trampoline skills against one another. Find out who can run the most circles around the trampoline, jump the highest, touch their toes the most times and more. You can even change it up and create patterns of movement that the other has to follow--whoever messes up the pattern first loses.