A report on getting water from...diesel exhaust? The Army is working on a system that extracts drinking water from military vehicle tail pipes.

Hamilton Sundstrand has modified two Humvees with prototype systems to extract the water from the engine exhaust. It can pull a gallon of water from every two gallons of fuel burned. The water is run through a series of filters that successively clean it until it is cleaner than most city tap water, and it is even chilled by the vehicle's a/c system. The downsides are: The system weighs about 500 pounds, You can only get water when the engine the system currenly 75-200 gallons of water before they have to be changed, and the engine has to stay running to get any water at all.

However, thay are also working on a system the size of a small fridge that will pull water out of thin air. This system makes about 600 gallons of potable water a day, even in the driest of deserts. Another poetntial user is NASA, who expect it to save the up to $10,00 a pound cost to lift water to orbit.

WSJ.com - Alchemy in the Desert?