Surprisingly enough this could well be a contender for my personal “Coolest gadget of 2005″ even though it’s devoid of batteries and blinking lights. Why? Because it’s a stunning example of a simple, well thought out and above all useful application of technology and design.

The lifestraw is a water filter. As with all the best technology though the devil is in the detail. Water filters have been around for years but they’re big, expensive and need constant replacement of the filters.

The lifestraw by comparison is as simple as they come. The filtering is done on demand - you literally put the lifestraw into any handy patch of water and suck through it. The result is clean drinking water in your mouth. For a whole year. For under $5. It doesn’t get much better than that!

The aim is to remove the bacteria that cause diarrhoea, dysentery, typhoid, and cholera. Granted it won’t remove heavy metals or industrial contamination but it should be a lifesaver for people in developing nations and if you’re a traveller you could do worse than stick one in your backpack for emergencies.

More details on www.lifestraw.com