"The City illustrates the emotional flow of the Presidential Inauguration in Washington, D.C. Through an analysis of the number of mobile phone calls made in Washington D.C. on Inauguration Day and the home state or country of phone origin, it is possible to see peaks of call activity as the crowd anticipates President Obama's oath, a drop in call activity as the crowd listens to his inaugural address, and peaks again as the crowd celebrates the inauguration of the new President. Through their cell phones, those present at the historic event share their impressions with friends and family in vast numbers: on the morning of January 20th, call activity is two to three times stronger than usual, and it rises to five times the normal levels after 2 pm as President Obama takes his oath and people begin to celebrate."

From http://gadgets.boingboing.net/2009/05/26/visualization-obama.html ...