Clay Filters
The LifeStraw

The easiest solution to water treatment might be one you hold in your hand. The LifeStraw works just like a normal straw, if that straw contained several different water-purification methods within it. Users can drink dirty water through the $5 straw, and the suction pulls the water through two filters and an iodine-filled chamber, cleaning the water of parasites, bacteria, and viruses.

The Slingshot

The inventor Dean Kamen has been working for many years on the Slingshot, a water purifier that runs on very little energy, and uses simple vaporization to purify the water (the water evaporates and then is cooled back into water in a separate chamber, the bad stuff stays behind). It produces about 250 gallons of clean water a day, and can clean anything from seawater to urine. Why hasn't the Slingshot solved our world's water problems yet? Currently, each prototype costs more than $100,000; Kamen's goal is to lower that cost to less than $2,000.

The Aquaduct

The Aquaduct, a concept bicycle by the design firm IDEO, solves two problems: unclean water and the long distances many people have to travel to get their water. The power generated by pedaling the Aquaduct pushes water in a holding tank through a filter and into a receptacle for drinking. Remember PlayPumps? When we first reported on PlayPumps-the water-pumping system that doubles as a merry-go-round and provides kids with fun along with clean water-some 700 units had been installed. That number is now over 1,000, and the organization hopes to reach a total of 4,000 by 2010. Donate today at playpumps.org.