The rocket stove, invented by Dr. Larry Winiarski, was developed to require much less cooking fuel than a traditional stove.  The rocket stove also emits less dangerously, as most of the energy burned turns into heat.  To build this rocket stove, you will need sheet metal or a 5 litre metal can, clay, water, sawdust, a wooden mold, a clay brick, vermiculite or perlite, and cement.  Learn how to build a rocket stove by watching this video tutorial.