I have been using my wonderful Water-to-Go bottle for three years now, and I love it. I have filled it from glacial rivers in Tajikistan, waterfalls in the farthest corners of the eastern Himalayas, lip-curlingly grotty taps in India, Pamiri puddles, Georgian springs and countless other ponds, lakes, puddles, taps and springs across Asia and South America. It has saved me using hundreds of plastic water bottles and allowed me to travel to the remotest places without having to lug around litres of bottled water. Not once have I become ill whilst using it. And all I have to do is change the filter every three months or so. I cannot stress how brilliant this ingenious bit of kit is: if every traveller had one, imagine how much plastic would be saved.