The future of urban density

We at Spore are essentially suburban. In spite of our living in and loving our city, we live in a single-family dwelling that has enough room that we can store things we don't mean to keep. We admire the minimalism borne of constraints, and we love what density can do for community vibrancy, as well as for environmental impact. Cities in the United States tend to have codes that prevent developers from building the kind of compact dwellings that are popular in many Asian cities, but some people are starting to explore the "what-ifs." What if there were a viable option for affordable, safe housing for the young and poor in our cities? What if semi-communal options were architectually supported? Today we read this interesting article in the New York Times on a few projects that are considering this, and we were inspired by the idea that we might see something like this in our cities in the next decade. We just hope, of course, that they want lots of doorbells.