I would definitely recommend at trip to the World of Coca-Cola museum while you're in Atlanta. The museum features tons of Coca-Cola memorabilia ranging from antique signs to an assortment of Olympic torches. Want to know what Coke flavors are available in Europe and South America? The Coca-Cola Freestyle area features over 100 variations of Coca-Cola soda from all around the world. For those who want a more interactive experience, a downloadable app now allows you to save your mixes and earn badges as you sample your favorites!
The World of Coca-Cola is only open for limited hours in the evenings though, so you will need to plan your visit strategically so that you don't miss out.