Oh wait – we already did! Why did we not raise a bunch of VC money and make this concept a start-up?
Check out Nextdoor:
and 7×7 article: http://www.7×7.com/tech-gadgets/nextdoor-and-san-jose-team-launch-private-social-networks-neighborhoods
They aren't "ready" for our neighborhood yet – but we could apply and start a community on their social network.
But already have our great Posterous uHood blog! We are so ahead of the times.