They say you should have food, gold, and guns. Food is a good idea. As long as no one knows you have it. Just stay inside as long as you can. You need gold to barter with. As soon as they know you have gold, someone will come to steal it. So you need guns. This way, the people who have come to take your gold will get pissed off and kill you and take your guns as well. Unless you are chosen by the Illuminati to be one of them, or one of their servants, you're going to need a lot of hard ass friends. Hopefully, you're friends will be like the guys with the gas in "Road Warrior", and not the guys outside. By the way, get some cars with carburetors. Any gas that's left will plug fuel injectors in a heartbeat.
Face it. If everything goes down the toilet, most of us are in deep trouble. The survivalists in Idaho have a chance, if only because they're readier than the rest of us.
Really, most of the survivors would be starring in "The Time Machine". As the Morlocks.