Hi Dan, nice to meet you.
I'd Like to share with you some links with similar projects.

I'm trying to bring a similar service on my Home town.

Currently I'm using http://project-byzantium.org/ which is a linux Distro with a free mesh network pre-configured.

After that, In Argentina there are a few free networks running over openWRT. They are http://buenosaireslibre.org/ and http://www.lugro-mesh.org.ar/ . The first one implement a client-server model and the second one a mesh network.

I hope this will be helpful for you, and I wish we could keep in touch to share experiences.