[great for dayhikes]
Just plunge this .75-liter sports bottle into the creek and start sipping. Testers loved the lightweight, low-effort method on long dayhikes in the Cascades, where water sources are plentiful. The .3-micron, pleated glass-fiber filter (attached to the cap) stops all protozoa and bacteria (not viruses), while an activated carbon element removes chemical contaminants.
You have to suck hard, but squeezing the soft, BPA-free bottle helps. Katadyn reports a 100-liter lifespan per filter (replaceable for $25), but we found 70 to be more realistic. Of course, the clearer the source water, the longer the filter life. $40; 8.2 oz.; katadyn.com