Cost: $19.99 [Link]
The LifeStraw is the invention that changed the developing world by providing a relatively affordable way to provide millions with access to clean and safe drinking water.
Used by hikers and other outdoorsy-types in the developed world for clean drinking water, this device could save your life if you’re unable to get access to clean water. LifeStraw removes 99.9999% of waterborne bacteria and 99.9% of parasites, and the family size unit filters out 99.99% of viruses. Considered the best invention of 2005 by TIME Magazine, it should give you 267 gallons of drinking water for each straw.