I ended up finding a page @ About.com with a list of thigns that you could grow in fall and winter. I can't find it (grrrr, have a copy printed @ home), but I just noticed there is a "Four Season Vegetable Gardening" forum here at GW that could be a great help.

You might check out Four-Season Harvest: Organic Vegetables from Your Home Garden All Year Long by Eliot Coleman (this is the book that was recommended to me by nearly everyone I asked about the subject). It's relative to Maine, but you should be able to tweak that to work for you down south.

I'm sure there are probably southern-specific publications you could get your hands on with a little hunting, but I'll be watching this thread just in case someone has done the legwork already and can post about it.

Actually, for GA-specific, Walter Reeves has a gardening calendar at his site, www.walterreeves.com, but it covers everything (not just edibles), and may or may not discuss planting during fall/winter. I can't recall (it's been a while).

I have some black eyed susans that lasted into January, Yuletide camelias bloom in December, witch hazel in Jan/Feb and Daphne in February. Daffodils in March.
There are chamaecyperis that have yellow and blue evergreen foliage that can brighten up the winter. Those could all fit in your spaces. You could also do red or yellow twig dogwoods. Winter isn't that bad, plus it's short. (I grew up in New York).