[QUOTE=grolbyBoiling water with your camp stove isn't an option. We didn't realize at first that we had the iodine tablets (we had very cleverly stashed them with our first aid supplies, and brought them along by accident!), and we wasted half of our stove fuel boiling perhaps a liter and half of water.[/QUOTE]

A lot of people are allergic to iodine so a system like First Need or the Katayn is idea.