the "lifestraw"

[faceless]

Mobilising LifeStraw? offers relief from the waterborne diseases of major public concerns such as Typhoid, Cholera, Dysentery and Diarrhoea. As a personal mobile water purification tool, LifeStraw? is designed to turn surface water into drinking water, thus providing access to safe water wherever you are.

http://www.lifestraw.com/en/high/instructions.asp

--------------

I just saw this on the news and thought it was brilliant - it doesn't seem to say how much they cost though, which has to be the biggest hurdle...