I'm one of those weird people stocking up canned and dried food for when/if the shit hits the fan in the United States (or if the Southeast, where I live, is wracked by tornadoes like we were a few years ago). I've got the food part of the situation taken care of, but I'm more concerned about the water issue.

I can rig up a water collection thing out of plastic 55 gallon drums, because I've read that the Coke bottling facility sells and/or gives their drums away in Birmingham, Alabama. If not, I should be able to buy, make, or steal ( as a last resort) something to collect water.

What I'm concerned about is water purification. If I collect rainwater or clean stream water, how would I purify it? Could I just boil it then filter it through clean cloth or coffee filters or do I need a still to boil it and collect it in a different container?