Couple of years ago on a tech forum I read of a person who was attempting to setup a neighborhood wi-fi network in his trailer park. Long story short, though the person was well versed in network technologies and had invested in some good equipment, he ran into quite a few issues in terms of range etc. In the end, he ended up creating a couple of centralized wi-fi hotspots under a picnic shelter type of setup and he found that the residents of the park actually enjoyed gathering around and under the shelter (depending on weather) with their laptops and being able to surf the net and at the same time enjoy some company and conversation with each other.

I would think this type of setup is more technically easier to setup in a centralized backyard of someones's home or local community meeting place then setting up a whole neighborhood wi-fi network in an age where most people struggle to find the Start button on their OS desktop. In a post disaster situation, it would also probably promote more of a community togetherness. As with anything, rules and polices would need to be established in terms of allotted connection time, hours of operation etc. To help save on bandwidth, a caching proxy server such as Squid could be easily implemented on an old laptop or pc.