holy crap little wing i just relised you signed up the same time as me and have 20 times the posts i do. i remember reading you weed newbie thread or what ever... i remember the weirdest shit. anyway a gravity bong and water fall are exsactly the same thing. its where you cut a carb in the bottom of the bottle and fill it with water let it drain out and smoke gets sucked in. a bucket bong uses simalar princables except you cut off the bottom of a bottle and lift it up in water and it sucks it in.