While most of the information on this site is about broadband networks at a citywide level, there are a variety of groups that are working to supply broadband at the neighborhood level (often in large metro areas). I have worked with folks in Saint Paul that want to establish a coop to deliver symmetrical broadband much faster that Comcast and Qwest (I hesitate to even include them because it will OF COURSE be faster than Qwest).
I just learned of the North East Los Angeles Internet Service Cooperative that is attempting to bring better broadband to a number of neighborhoods in LA. They have run into many of the same barriers I saw in Saint Paul - organizing people for better broadband is difficult. People are intimidated by technology and reticent to pledge the necessary funds needed to launch a cooperative.
At this point, the NE LA Coop is more of an idea than an entity that can deliver service, but it is educating people about the benefits of moving beyond monopolistic incumbents. The person responsible for the idea, Jared, has a number of innovative ideas that may prove very interesting and demonstrate the innovative potential of networks freed from the rules of incumbents.
For instance, by aggregating or sharing the connections of multiple subscribers, individual users may find a boost effect in their surfing. By sharing connections, users can take more control over their networks (and their privacy) - but massive companies like Comcast and Time Warner don't allow users to do this. Community networks may be more accommodating -- especially if required to be when created. To any who find this improbable, remember that when we own the network, we make the rules.