SteriPen Traveler $129 Magellans.com

Small enough to carry in a pocket, the device uses UV light to purify a 16-ounce glass of water in less than a minute. It can be used in restaurants, hotel rooms or on the road.

It works by destroying the DNA of micro-organisms. The SteriPen comes with two non-rechargeable CR 123 batteries and a padded carrying case.