This free educational site (with nothing for sale) will interest those who would like an INDEPENDENT way to communicate with others up to a few miles away, without relying upon any infrastructure or installations.  

The site’s name represents its topic:

Simplex COOPerative Relay.

By relaying from one site to the next, messaging can extend for many miles, and quickly.  It is done by radio — using inexpensive handheld transceivers and plain voice. There is no need for external power or facilities, because “simplex” means direct from radio to radio — ideal in emergencies when the grid is down.  Participation does not require any memberships, dues, or duties.    

SCOOPR is personal-safety radio for communities or local areas, providing a way to contact each other and the world outside when the electric, phone, and internet systems unexpectedly fail.  (This site summarizes the material discussed in more detail in the Kindle book “Personal Safety Radio: Keeping In Touch When Cellphones Fail”.)
If your interest is mainly on wilderness travel and emergency messaging, try the related site ARRUMBA.net, which concentrates more on using repeaters and two-way communications about your location & status from places with no cellphone coverage.