Ultra Stomp Rocket
No batteries, no gun powder, no electricity. Just good old fashioned oxygen. And these babies fly up to 200 feet in the air... or plenty far enough to hit your little sister in the face from the other side of the room. Stomp Rocket Ultra (I wonder how crappy the Stomp Rocket Non-Ultra is...) comes with 4 rockets and could possibly be ruined by teachers around the world trying to illustrate physical principles like trajectory, projection, force and motion rather than letting kids just jump up as high as they can and land on it to see who can achieve the highest or furthest launch.