I briefly considered building it over an afternoon, but I'm not sure it would really work on the Internet. My gut feeling is that within a few days it would be

I briefly considered building it over an afternoon, but I'm not sure it would really work on the Internet. My gut feeling is that within a few days it would be full of spam and inane comments, because there's absolutely no sense of having a shared responsibility for a physical place in your neighbourhood. It's also unlikely to build the same sense of community from people stopping at the same time and talking to each other.