Nanoscale carbon, for example, is enabling greater efficiency and longer lifetimes for the familiar activated carbon water filter.

FORBES: Innovation: Water's Life Saver

Leiba says that activated carbon water filters -- like Brita pitchers or faucet attachments -- are a safe and affordable option for filtering tap water.

CNN: Is your bottled water safe?

Women were gathered around a motion-activated faucet that dispensed water from the holy spring.

NEWYORKER: The Sanctuary

The architects worked with Pureti, a green-tech manufacturer (and winner of a 2011 "What's New" award from Popular Science), to develop a spray version of a titanium nano particle that, when activated by sunlight, oxidizes airborne particulates and converts them into water vapor and trace amounts of carbon dioxide.

WSJ: Turning Up the Volume in Public | By Julie V. Iovine