Via Wired: http://blog.wired.com/wiredscience/2008/03/colbert-and-kam.html
Dean Kamen, the prolific inventor of the segway, ibot, insulin pump, etc. has developed a water purification machine driven by the relatively obscure sterling engine. The above link profiles the “slingshot” and includes a video of Kamen on the Colbert report. Hilarity ensues…. 
Some great quotes from Dean Kamen:
“50% of all human disease is caused by water borne pathogens.”
“Just to make an ordinary bottle of water takes about 5 liters of water to make one liter of bottled water.”
“It takes 250 gallons of water going into a cow to make one quart of milk.”
That is incredible. How is that done on the water filtration? What happens to the filtered out crud? Can I get one of those? Is it a total secret as to how it is done? So many questions, so little time! Appreciate the awareness on this! Lots of villages and hospitals in 3rd world countries could use this. Hopefully, the U.N. won’t be the distributor of this because they will fraudulently re-route the units and funds into agent coffers just like in the food- for-petroleum gaff with now deceased Saddam Hussein and his former thugs in Iraq.