I think Groo has the right idea, sharing is benificial to your long term survival. And food for the first few days down here wasn't a problem, with long term power outages people are eating well in a lot of neighborhoods just to keep food from going bad. So instead of eating C rations you could be eating grilled steak.

I never really thought of it as bartering but i have some things that i intended to share. I have a chainsaw and two generators, that makes me kind of popular. By letting my neighbor borrow one generator he gets to go out and find an open gas station and wait in line, yes i had enough gas on hand for a couple of days but we still have no power and it is not expected to be restored for a couple of more days. We also work out our schedules so that someone is around to tend the generators and keep an eye on things. I don't loan out my chainsaw but i will use it to help out others, if you are clearing trees and limbs it helps to have someone cutting and a couple of others clearing the just cut material out of your way. Just be sure they understand the safety precautions of working near someone with a chain saw. So working together can be benificial to riding out the aftermath of the storm.

My personal belief is that you should know your neighbors before something happens, that way you have an idea of who will help out, who you should help out, and who you should watch out for.

Ethical question? You have a nosy retired little old lady neighbor who isn't really going to be much help in the aftermath of a disaster, would you help her out? She can be a bit of a bother alway wanting to know what is going on in the neighborhood, she is old and is going to die soon anyway, right? She might also be the reason you have your supplies at hand, she is the one who is most likely to call the authorities when a panel van is in your driveway because she knows that you are away on vacation and your house doesn't need any repairs. Is she deserving of your help now? Knowing your neighbors beforehand means that yes you might wind up sharing but it also means that they are less likely to try and take what you have, just a thought.