Oh yes, adults can and do show their chickens! There is SO much more to it than 4-H, some chicken exhibitors get really serious about it (guilty as charged.)
I looked on the American Bantam Association website for sanctioned shows in GA, and found these:
Fancy Fowl Club of Georgia
Date of Show: 2009-10-24
Type of Meet: Special
Contact info:
Fern M. Herrington
[email protected]
Northwest Georgia Poultry Club
Date of Show: 2009-09-12
Type of Meet: Special - double show (which means two shows in one spot!)
Contact info: Bob Bridges
[email protected] 706-602-1358
You can collected points/stars with the ABA and the APA (American Poultry Association), each has their own system (you must be a member though.)
As well, there are breed clubs for most breeds of poultry, which have their own awards/points systems to work towards.
Chicken shows are totally different than horse shows, with the nice part being all the work is done ahead of time, the day of the show you coop your nice clean bird into a cage and then you're done until after judging.
I've written a couple of articles on my website about getting ready for shows, see them here:
What to Expect at your First Poultry Show:
http://www.pathfindersfarm.com/Showing.html
Conditioning and Prepping for Shows:
http://www.pathfindersfarm.com/Prepping.html
This should give you a start, let me know if there's anything else I can do to help.
Best,