An interesting interactive map here shows the migration patterns of people in 2008.  Click on any county, and it shows (in black) how many moved into that county (and from where), and (in red) how many left that county (and to where). 

Here's the migration patterns relating to Forsyth County, NC.

Looks like this county had more incomers than outgoers, with most of the newcomers from New York, New England and Florida.

And if you click just about anywhere in California, you'll see that people are leaving it in droves.