Probably everybody's favorite science class staple, dry ice is a very practical substance beyond its theatrical properties. Before the advent of cheap, reliable refrigeration technology dry ice was key to getting perishable products to market across long distances. It's still widely used today in the medical and scientific fields to keep things cool. But for most people, it's the volatile nature of dry ice that makes it so amazing. Especially the wispy fog it creates as it goes directly from solid to gas. YouTube user KipKay designed this clever coffee can fog machine to maximize the output and add instant atmosphere to any occasion. One important reminder: dry ice is carbon dioxide and without proper ventilation, can displace the oxygen in an enclosed space.