You guys are all doing it wrong. Gravity bongs are fine, but the best way to do it is to get on a free fall ride that actually pulls the people on it towards the ground. That way, you're falling faster than the force of gravity. Then, you use any type of bong, gravity bong works fine too, and you let the force of you falling push everything into you, so then the smoke gets compressed in your lungs, getting you even more high.