The Census Bureau has just released the latest county-based population estimates, with a reference date of July 1, 2007. You can access the data here:
http://www.census.gov/popest/countie...ST2007-01.html
If you know the components of your area's MSA and/or CSA (this can be found on the census site also), you can now calculate the population estimate for July, 2007. Here's Atlanta:
Atlanta Sandy Springs Marietta MSA 2000: 4,281,616 /
2007: 5,278,904
The Atlanta CSA adds the Gainesville, GA MSA, and the micropolitan areas of Cedartown, GA, LaGrange, GA, Thomaston, GA, and Valley, AL:
Atlanta Sandy Springs Gainesville CSA 2000: 4,583,958 /
2007: 5,626,400
The Atlanta MSA has added 997,288 and the Atlanta CSA has added 1,042,442 people, since 2000. The Census Bureau noted that, in the 2000 through 2007 period, Georgia had 18 of the nation's 100 fastest-growing counties, leading the nation in that number, and three of the top 10, also leading the nation in that number.