A thought:
Anyone with, or planning to have, SSB mode capable communications gear, will be able to communicate computer to computer using that equipment, as well as using it for traditional voice communications.
Using a technique called PSK31 the range of SSB capable radios can be increased considerably beyond that of normal voice communications, and of course transmitting digital code will reduce the number of people who will be able to interpret that communication.
PSK31 is computer keyboard and screen display between two or more computers. It uses radio waves to transmit and receive digitised messages through SSB capable transceivers. Unlike this forum or e-mail, it is not asynchronous. Its live communication, like talking, although short bursts of text ( messages) are prepared effectively offline and then transmitted as a burst of data. This is quicker than live data transmitting for those of us who are slow at typing.
The good news is that the software needed to be able to operate an SSB capable radio in PSK31 mode can currently be downloaded from the Web as freeware. Although interface cables are preferable, they are not mandatory so just using the software, a computer with sound card, loudspeaker and mike in close proximity to the radio will be effective.
Freeware software can be downloaded here:
http://www.digipan.net/
PSK31 is most probably not going to be legal to use on the soon to be allowed SSB CB standard. It is a Ham-only methodology at this time. But it will work over any SSB capable transceiver, SSB CB included.
With the downloaded software, and a suitable transceiver or SSB capable shortwave receiver, we can immediately ( and legally) listen and interpret PSK31 transmissions from around the world.
So, as a free of charge capability for a potentially grid down world, it may be worthwhile downloading?