Liquor.
Learn to distill liquor. If everything ever does collapse it will be one thing that can be easily bartered and can be used as antiseptic...
I've got a total nut job buddy that spent a good bit of time in Laos when we weren't there so to speak, I think that's the most useful thing he's ever said to me...
Problem I have with this is that we are at the point where making liquor is a good idea, then the corn and sugar will be more valuable as food than booze. My other thought on this is that you can buy liqour pretty cheap right now. A couple of gallons of Everclear stored in glass bottles would last a lifetime for the majority of folks.
I am also not real keen on the idea of bartering in intoxicants or weapons.