Pete just showed me this website, which I find very interesting.
A simple idea… which if adopted on a large scale could really make a bit of difference in the way we know and communicate with out neighbors… in the words of the creator on why Neigbornode was invented:

Neigbornode was developed because the Internet, while really good at connecting people half-way around the world, is really bad at connecting people who live across the street from each other (or a block from each other, or two blocks from each other). This can be liberating on one hand, but there are still lots of advantages to be gained by sharing information locally and opening lines of communication with others in your immediate area. The Internet for the most part has not cashed in on these advantages. Neighbornode addresses this issue by creating spaces for people in the same area to communicate easily with one another via the Internet, and by then building these separate spaces into a network, so that information can travel between locales as residents of those areas see fit. In this way, Neighbornode bridges the gap between the Internet and the neighborhood.