That's a question that I'm pretty fascinated with personally. When it comes to communications after a major disaster, we continue to plan to rely primarily on '

That's a question that I'm pretty fascinated with personally. When it comes to communications after a major disaster, we continue to plan to rely primarily on 'conventional' radio via e.g. clear-channel AM radio stations and other major commercial broadcasters which have worked with the government to prepare solid contingency plans. For this reason, it's a good idea to own a portable radio or two even though you wouldn't normally use them, and to familiarize yourself with an AM news station (e.g. KCBS 740 KHz in the bay area). Of course, for two-way communication we are all quite dependent on our cellphones. The cellular networks own mobile equipment and other provisions for providing service in a contingency situation, and ideally there could be no interruption in service (as the generators at many cell sites could hold them until service crews arrive, in the case of loss of electricity, for example). But in practice it's easy to imagine a few scenarios that would have the cellular network significantly deteriorated in a region for days, such as a major earthquake that damaged infrastructure and made it difficult to get equipment and fuel to the area. In the short term, I wouldn't count on it. In the long term, the effort involved in restoring cellular service could be enormous but it would be a reasonably high priority. It'd be a good idea for more people to own accessible point-to-point radio equipment with a decent range. I don't know how to achieve this though. CB equipment is bulky and now relegated to its own particular subculture. The amateur radio industry has produced a lot of high-quality handhelds but they're designed to be the opposite of accessible. There have been some ideas based on peer-to-peer relay between mobile phones but the range remains very limited. Maybe someone could come up with a good product in this space.