How's this for a good idea: An oversize drinking straw that sucks clean water from a tainted mud puddle, works for up to a year without servicing, and costs roughly three bucks to make.

   Oh, and could prevent perhaps 6,000 deaths per day if distributed throughout the world's poorest countries, where even filthy water can be scarce and distant, and clean water is only a dream.

   Meet LifeStraw, the invention of a Swiss-based weaving company called Vestergaard Frandsen that started out making blankets and shirt fabrics but is now focused on "disease control textiles," such as the insect-killing tarps and netting it distributes in earthquake zones.

   This ingenious water purifier is a tube about 10 inches long and an inch in diameter, with a string that lets it be worn around the neck. Inside are a series of fabric filters, some activated carbon, a bacteria-killing resin and little iodine. In combination these can capture or kill more than 99 percent of waterborne bacteria and parasites. Viruses can still get through, and so can arsenic, but LifeStraw prevents dysentery, typhoid, cholera, salmonella and many other nasty diseases.

   It's no replacement for the spendy water filters familiar to American backpackers, they have finer ceramic filters and don't deliver an iodine aftertaste. In much of the world, though, 700 liters of virtually disease-free water is not only a bargain at $3 but a blessing at any price.

   Vestergaard Frandsen isn't retailing this product and doesn't plan to. Instead, it sells LifeStraws in bulk to charitable organizations for distribution in areas of need. They've become a favorite of several Rotary chapters in Britain, and the company would be delighted to hear from American groups interested in sponsoring LifeStraw deliveries.