A rocket stove is a small, portable, lightweight cooking alternative designed for when you're out and about in the wilderness, on the beach...or at a campsite! You can burn biomass, small diameter wood, or solidified fuels in these little systems, and they're a great alternative to liquid fuel stoves (and cheaper too!).  They work by creating a combustion chamber from the air vents at the bottom to a narrower opening at the top where you can place your grill or saucepan.  There are many shapes and sizes, most of which are designed to fit right into your backpack! Handy for emergency heat or that hot water you may need!