Now this Solar Bottle is one neat idea - it was specially designed to obtain the maximum effect from a natural phenomenon that will be able to purify disease-ridden water.

Water, when left in a transparent PET bottle and under direct sunlight, will be purified to a certain extent courtesy of heat and irradiation from UV-A rays.

Designed by Alberto Medo and Francisco Gomez Paz, you can stack this bottle on top of one another easily, where each individual container can hold up to 4 liters of water. No idea on when this design will be put into production, but better sooner than later I say.

Source: Ubergizmo