gihan_ripper writes "British inventor Michael Pritchard has developed a small self-contained filter system that instantly cleans water, removing all particles larger than 15nm. He said that he was inspired after seeing the effects of Hurricane Katrina and the Boxing Day tsunami in 2004; people had to wait for many days to get fresh water and many died from drinking contaminated water. The filter is so effective that it can purify dirty river water and even fecal matter. His bottle will shortly be available for sale from Lifesaver Systems at an expected cost of £190 (approx. $385)."
You see but you do not observe.
Sir Arthur Conan Doyle, in "The Memoirs of Sherlock Holmes"