In early 2009, low- and middle-income families in San Bernadino, CA moved into a smart growth community development called The Preserve.  The purpose of this project was to examine children's physical activity behaviors in the immediate contexts in which they occur.  Families selected to move into The Preserve were compared to those who were not selected.  The study determined whether moving to a smart growth community influences children's exposure to and experience of behavior settings and contents conductive to physical activity.  Real-time data was captured using the Ecological Momentary Assessment with mobile cell phones.  Accelerometers, neighborhood audits, and GIS were also used to collect objective physical activity data.