One of my hunting buddies always starts his day off with a Diet Coke. Once I took a needle and poked a strand of thread through a couple of mentos. I then suspended them under the cap with the threads of the cap pinching down on the loose ends of the thread. I was a nice guy and handed him his Diet Coke as we sat in front of the campfire for breakfast. When he twisted off the cap the mentos dropped into the bottle and turned it into a soda volcano! At least 1/2 of those 20 oz. spewed right in his face as he went in for the first sip after cracking it open. He was a better sport about it than I would’ve been first thing in the AM.