Here's a brilliant bit of engineering: A straw that purifies water as you sip through it -- allowing people to drink directly from rivers and lakes that are otherwise fatally ridden with bacteria. A creation of Vestergaard Frandsen, a firm that specializes in "disease control textiles", the LifeStraw is aimed squarely at developing worlds plagued by bacteria such as Salmonella, Shigella, Enterococcus and Staphylococcus.

How precisely does it kill those bugs? As medGadget reports:

What first meets the water when sucked up is a pre-filter of PE filter textile with a mesh opening of 100 micron, shortly followed by a second textile filter in polyester with a mesh opening of 15 micron. In this way all big articles are filtered out, even clusters of bacteria are removed. Then the water is led into a chamber of iodine impregnated beads, where bacteria, viruses and parasites are killed. The second chamber is a void space, where the iodine being washed off the beads can maintain their killing effect. The last chamber consists of granulated active carbon, which role is to take the main part of the bad smell of iodine, and to take the parasites that have not been taken by the pre-filter or killed by the iodine. The biggest parasites will be taken by the pre-filter, the weakest will be killed by the iodine, and the medium range parasites will be picked up by the active carbon. The main interest to everyone is the killing of bacteria, and here our laboratory reading tells us that we have a log. 7 to log 8 kill of most bacteria. This is better than tap water in many developed countries.

That simply rocks.

(Thanks to Engadget for this one!)