The Corporal does another great review here on water filters. Just boiling water that comes from a questionable source will NOT kill all bacteria and protozoa. In the video below the Corporal explains 3 different water filters and puts them to use. All three filters will get the job done. I prefer life straws, they are compact and cheap. Other water filters on the market are MSR and Katadyn. They always puts out decent products but the price is a bit higher. A water filter is a must have in any go bag, even in your daily driver would be a good place to keep one just in case.