Forbes online has a great map that shows whether everybody is moving into or away from your county as of 2008. Jut click on any county on the United States map and it will show you RED for leaving and BLACK for incoming. Leaving the mouse over a county shows some demographic information as well.
Here’s Dallas county as an example. A lot of incoming and not a lot of outgoing.
Dallas County 2008
Miami-Dade Country as another example. This one is just slightly different than Dallas.
Miami-Dade 2008
