$10 cardboard box saving lives, the world.

From News.com.au:

A $10 cardboard box that uses solar power to cook food and sterilise water has won a $100,000 science prize for ideas to fight global warming.

The "Kyoto Box", named after the United Nations' Kyoto Protocol that seeks to cut emissions of greenhouse gases, is aimed at billions of people who use firewood to cook.

Costing just €5 ($9.20) to make, it can also make it easier to boil polluted water.

"We're saving lives and saving trees," the Kyoto Box's developer Jon Boehmer, a Norwegian based in Kenya, said.