3. Williamson County, TX

Towns include: Brushy Creek, Georgetown, Round Rock
Job growth (2000-2010): 68.1%

What`s the key to jobs growth in Williamson County? It could be smart people. Round Rock, the area`s commercial hub, boasts that 40% of its residents have a college degree, with 70% of them having some sort of post-secondary education.

Providing jobs for smart people in Round Rock since 1996 is Dell Computer, Williamson County`s biggest employer. Dell has some 15,000 employees here, with plans to add more to staff its new customer solutions center.

Also hiring is Emerson Process Management. The company, which creates automation technology for heavy industry, is relocating 750 employees to town, with another 125 jobs expected in the next three years.

Before:

1. Rockwall County, TX

2. Loudoun County, VA

Next:

4. Douglas County, CO

5. Hamilton County, IN

6. Delaware County, OH

7. DeSoto County, MS

8. Utah County, UT

9. Ascension Parish, LA

10. Campbell County, WY

11. Livingston Parish, LA

12. Larimer County, CO

13. Prince William County, VA

14. Rutherford County, TN

15. Wake County, NC

16. Williamson County, TN

17. Sarpy County, NE

18. Shelby County, AL

19. Carver County, MN

20. Hendricks County, IN

21. Charleston Country, SC

22. Cache County, UT
23. Madison County, MS
24. Canadian County, OK
25. St. Croix County, WI