Census Bureau Population Estimates: PopClockshttp://www.census.gov/popclockDaily US and World Population Estimates from the US Census Bureauen-usNonehttp://blogs.law.harvard.edu/tech/rssUS Population Estimate: 319341986 on nowhttp://www.census.gov/popclockFederal Government StatisticsWorld Population Estimate: 7207863020 on nowhttp://www.census.gov/popclockFederal Government Statistics