Sawyer 4 Way Water Filter - 34oz water bottle with in line filter that can also be removed and used in line with a standard hydration bladder, on your home faucet, as a stand alone unit or use the bottle by itself with chemical purification tablets.
Katadyn MyBottle Water Purifier - Blue Splash: Drink from virtually any fresh water source. Just fill the bottle with the water you want purified, and insert the specially-designed Katadyn purification system. http://www.filtersfast.com/P-Katadyn-MyBottle-Blue-Splash-8017756.asp
the RescueMe Balloon takes a different approach. Rather than relying on combustible chemicals that burn out after a while, the RescueMe system deploys a large helium balloon into the air. The bright orange balloon can stay aloft for up to seven days, and is outfitted with flashing LED lights for extra visibility at night.