If you are into the more adventurous type of travel, this portable ultraviolet filtration and sterilisation kit will make it possible for you to turn any cruddy old water you find into drinkable H2O. A pre-filter filters the particles out mechanically, then the water is subjected to concentrated UV light, produced by the AA battery-powered Steripen itself, which kills off bugs.
As one who finds even clean tap water a bit worrying because of the thought that every molecule has probably been through thousands of sets of kidneys in its time, I have to say, I’ve always been impressed by the fortitude of explorers. So while I’d love to say I have tested the Steripen by imbibing a litre of sludge from a puddle, I’d be lying. It’s a serious product and rigorously tested, but not by me, sorry. I also think if I were extracting water from a stream in the wild to survive I’d be tempted to double up (probably unnecessarily) by using sterilising tablets after the Steripen treatment.