I second that – The Lady & Sons has moved since we were there (Paula wasn’t famous then), but I’m sure the food is just as delicious. And it was so good, we ate there twice in one week! Have the chicken pot pie; it’s to die for. Which is good, because it’s really bad for you. 
Other things… just walk around the old town. It’s gorgeous. The squares are lovely, and Forsyth Park is nice, too. If you’ve read Midnight in the Garden of Good and Evil, you can drive out to Bonaventure Cemetary and see some of the graves mentioned in the book. Even if you haven’t read it, it’s an interesting place, but it is kind of a drive out. We found a smaller, older cemetary in town (I don’t recall where, but it’s on the tourist maps, I think), and we found it even more interesting. Bonaventure is one of those cemetaries you mainly drive through, but this one you walk around. It’s so old that it’s fascinating – old script (“Here lief John Jonef” and all), old sayings, old stories. We really liked it. Go to the visitor center, too, I think there’s a museum there. We went there for our honeymoon, and it was perfect because it’s one of those towns where there’s enough to do that you’re not bored, but not so much that you feel like you’re missing out if you don’t get to it all.
Since you don’t have a lot of time, you might want to take one of those bus tours. We did, and it was a great way to see a lot of the city and get the background info, too. My other opinion on food – don’t go to Mrs Wilkes’ Boarding House (or whatever) unless you want family-style food, and no choice. I understand that the food is decent (and cheap), but with only a day there, I would choose to spend more for food, because it is such a part of the South. YMMV, of course, but I would have been disappointed.
Oh, another idea – see what’s going on at SCAD – they might be doing something that interests you!
Have fun – we loooooved Savannah. If we ever win the lottery (ha ha! we’d have to play, I’m told), we’ll buy a winter home in Savannah. 