Colleague Owen Densmore points us to this page with these comments:

This use of gps may play a role in understanding economic development in any city by watching the flows within the city:
http://digitalurban.blogspot.com/2008/12/gps-city-tracks-1-year-in-24-hours-via.html

This gets me to an aspect of ED I'm interested: MicroED.  It comes from the observation that all cities' ED is unique.  Think about every city you've lived in and you'll notice that each was unique.  For me, Rochester NY: Kodak/Xerox company towns; Silicon Valley: A network of startups and established companies with a highly mobile social/skill network.  Here in Santa Fe, we are similarly unique. ...   more »