[Fjolsvith]

Are there inexpensive technologies that allow line of site communication across 5-8 miles? Something that could be erected on the top of a barn or windmill, that would mesh and route among adjacent nodes?

Something like that would allow communication across the countryside and allow communities to interconnect irrespective of the existing monopoly infrastructure.

[grahamburger]

Yes, what you're describing is a WISP* and they're fairly common in suburban and rural communities in the US (and other places I just know the US best). Some of the companies that make equipment for this are Ubiquiti, Mimosa, BaiCells and Cambium.

* https://en.wikipedia.org/wiki/Wireless_Internet_service_prov...