From Boing Boing, how to filter water with an interesting recipe. Especially useful when you don’t have money or means for our more sophisticated water purification methods.

The link is from worldchanging.com,

A handful of clay, yesterday’s coffee grounds and some cow manure: the ingredients that could bring clean, safe drinking water to much of the third world. The simple new technology, developed by [Australia National University] materials scientist Mr. Tony Flynn, allows water filters to be made from commonly available materials and fired on the ground using cow manure as the source of heat, without the need for kiln. The filters have been tested and shown to remove common pathogens including E-coli.

“They are very simple to explain and demonstrate and can be made by anyone, anywhere,” says Mr Flynn. “They don’t require any western technology. All you need is terracotta clay, a compliant cow and a match.”