I remember the days of dropping large white water purification tablets into the murky liquid in my sigg flask then attempting to slake my thirst on something that tasted like I imagine a chemical toilet would. Then came the Water-to-Go Filter Bottle.
Water-to-go is an all in one filtering solution. You simply fill the flask with water, screw the top on and drink. By sucking on the flip-up straw you draw the water through a filter whose teeny-weeny pores filter out just about everything. I drank water from mountain streams, waterfalls and even something a little more stagnant in Durmitor National Park. It all tasted absolutely clean and fine.
I have not suffered any problems and it is supremely simple to use; light, healthy and easy.