The Connected States of America illustrates the emerging communities based on the social interactions through the use of anonymized mobile phone data.
Investigating the interaction network of people reveals interesting facets on how people utilize space. Cities attract their citizens from all walks of life, from nearby and from distant areas across the country. This constant flux of people commuting, migrating, and travelling across the country establishes connections which are dominated by large cities. The social connections woven across the United States can be used to define communities, where the glue that holds a community together is a stronger relationship with other members of the same community compared to members of other communities. Naturally, one can ask whether the communities defined purely by social interactions coincide with the administrative boundaries, for example state boundaries? Remarkably, this is not always the case!
See http://senseable.mit.edu/csa For more visualizations and information.