We try so hard in American cities to get an active pedestrian street scene to happen.  In China, with a billion people and 17 million in Shanghai alone, there never seems to be an issue with action on the street day or night.  And, of course, where there are people around, cool things just seem to happen serendipitously.  On Nanjing Dong Lu in downtown Shanghai the mixture of aggressive retailers, garish signs, bustling crowds and lots of hawkers is complimented by ballroom dancing in the street and slackers just hanging out.  What a scene!