This is so cool. Mentos and diet soda combine to produce an amazing erruptive effect. Check out the video here. Apparently,the mentos provide nucleation sites for the bubbles, then the bubbles push the soda out of the bottle. And as anyone who's poured warm diet soda knows, the foam is more long-lasting than your typical non-diet soda foam. The two together produce the remarkable effect shown in the video and in the photo at right. I'm totally doing this for Easter.