LifeStraw: invention of the century?

The aptly-named LifeStraw... is a personal, low-cost water purification tool with a life time of 700 litres - approximately one year of water consumption for one person... that could become one of the greatest life-savers in history. It is a 25 cm long, 29 mm diameter, plastic pipe filter and purchased singly, costs around US2.00. (source)

Clean water for a year for just two bucks? -  sounds good to me! WorldChanging provides a good summary of the product, though I don’t understand why the promotional pictures have people kneeling down and drinking directly from riverbeds instead of from cups or bowls. Seems like this simple step could drastically increase the effectiveness and life of the product.