We’ve just added a unique and handy water filter to our line of camping equipment. The Aquamira
Frontier filter is basically a straw with a built in filter and can
handle up to 20 gallons. The other one is Katadyn Pocket Water Filter, read review: http://www.greatoutdoorproductstore.com/katadyn-pocket-filter-review/
You can bend over a stream and drink directly
from the water through the filter. This method has little chance for
cross contamination and makes a great back up for your camping gear.