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: 320729034 on 2015-04-21 04:44:34http://www.census.gov/popclockFederal Government StatisticsWorld Population Estimate: 7238313002 on 2015-04-21 04:44:34http://www.census.gov/popclockFederal Government Statistics