Some animals don't drink water — and now some factories might not, either. The potatoes that PepsiCo turns into Walker's Crisps — those sinisterly addictive potato chips that people in the UK can't seem to get enough of — arrive at the factory containing as much as 80% water by weight. So why not harvest it rather than sending it up the chimney as steam?

PepsiCo's new efforts aren't motivated solely by a desire to spruce up its corporate image: Water, an increasingly scarce resource, costs real money. The company believes it can save up to $1 million a year by recovering the water that it boils off of its potatoes as they fry in oil. Next up: making the artificial flavors in crisps from something other than fossil fuels.