None of what follows is rocket science, and it's not the place to look for thoughts on 2.0/3.0, social software, or urban informatics. That would be in the accounts of different projects. But if you're interested in the honest craft of website work, almost deliberately old-fashioned 'classical' web design -- and how to ally this with innovation in magazine publishing -- the following should provide a decent account of several of the key decisions in this particular project.
Dan's thoughtful approach should be required reading for anyone building media web sites.