Light-weight, tiny, and easily doable, Mark Jurey's penny stove instructional demonstrates how to make a sleekly simple (and cheap) camping stove.
First off, how does it work? Luckily, Jurey explains:
"Burning fuel in the center and outer ring of the burner heats the cup and fuel. The heat causes fuel in the the center to run under the penny into the cup and start to boil. Fuel in the outer ring lights the six jets as gasses are released from boiling fuel in the cup. The pot and wind screen reflect the heat and accelerate the heating process. The base insulates the hot cup to maintain a stable boil.
Jets continue to heat the burner and lip of the cup, increasing the boil and producing a full flame. Windy conditions will blow flames into the cup lip increasing the boil and flame size. As heat builds up, pressure forces gasses under the penny to produce a central flame. As the fuel level falls (or simmer ring is added), pressure falls and the penny seals to force all gasses out the six jets maintaining stable heat to the cup and optimum flame size to the pot."
For Jurey's detailed instruction on how to do-it-yourself, click through. Sample instructional images: