I'd hate to live in the middle of a large city when something hit the fan. Even if the danger from the radiation was nil, the danger from your "fellow citizen" would not be.

Smaller communities might do quite well, if someone does a bit of organizing. Nuclear fallout from an atomic attack degrades very rapidly, and assuming you were outside the effects of an actual blast, a week or two inside a shelter would take you past most of the fallout danger level. Fallout will not make other things radioactive, like canned food.

Even assuming you don't want to go to the work of assembling an emergency supply of food and water from normal sources, you can get pre-packed units from several sources.

At the worst-case far end, you can get a year's supply of nitrogen-packed food for a family of four for about $3,000. A week's worth of such long-term-storable food costs about the same as an IPod. Water storage is critical, and purifiers are a good investment. In a pinch, few people are aware that the water in an upper toilet tank is drinkable, never mind the water heater.

For most normal emergencies, a three-day supply of essentials is usually enough.

In an emergency, it often seems that a lot of people die of ignorance.