I meant to post on this earlier. Read it over at Dean's World.
A researcher named Ashok Gadgil first developed a way to use ultraviolet light to kill bacteria in water, giving a lot of people drinkable water at a price that could be afforded. Now he's found a cheap way to filter arsenic out of drinking water; if it indeed works out, this man will have saved literally God only knows how many people by his work, and made their lives a lot better.
Not a whole lot of people manage to do such a thing. Check it out.