Re: Rural networking
It's not a new idea at all. Years ago I read about the installation of a working telephone booth at the Burning Man festival, using a chain of off-the-shelf routers strung across the Nevada desert. It's just that it's getting more affordable, and the RPi lets you integrate things like battery and power management to a greater degree. There are also quite a few routers that one can "jail-break" and convert into small fully programmable Linux boxes. (OpenWRT, etc.)
A related idea would be just to use a pair of solar-powered RPIs (or OpenWRT boxes) to wirelessly bridge a road. This is useful, because while you might persuade a few landowners to let you string a fibre across their land, just try getting permission to take a fibre over or even under a public highway. So, don't try. Just put a solar-powered fibre-to-wireless router on each side. You wouldn't even need directional antennae (which may not be entirely legal).