by Patricia Sellers

Greetings from Atlanta. I’m here for Fortune‘s “Most Powerful Women Evening With…” Atlanta is tonight’s stop in a series of regional dinners that we’re hosting annually in addition to the main event, the Most Powerful Women Summit. I’ll be interviewing Food Network star Paula Deen, the silver-haired, Southern-cookin’ entrepreneur and star of the Food Network. Also with us: the top women execs at companies like Coca-Cola KO , Home Depot HD , Delta Airlines, DAL , UPS UPS , and Turner Broadcasting, which is part of Fortune‘s parent, Time Warner TWX .

It’s fascinating to be here since I grew up, career-wise, learning about business from two Atlanta-based Fortune 500 giants: Home Depot, back in the ’80s and ’90s when co-founders Bernie Marcus and Arthur Blank were running the place, and Coca-Cola, when the late CEO Roberto Goizueta built Coke to be Fortune’s No. 1 Most Admired Company.

Isn’t it interesting that a false sense of invincibility and arrogance eventually poisoned both corporate cultures? Coke and Home Depot fell off the tracks, struggled through lines of wrong CEOs, and had their comeuppance. Only after painful cost-cutting and serious strategic rethinking did they begin to return to prominence.

I spent this morning at Coke with some folks who’ve been key to its recovery. One is SVP Wendy Clark, a hotshot marketer who joined Coke last year from AT&T ATT  and this year made Fortune‘s “Women to Watch” list in the Most Powerful Women issue. I also caught up with Clyde Tuggle, Coke’s global communications chief whom I’ve known since the ’80s, the Goizueta days.

Talking with Tuggle reminded me how radically marketing has changed. In May, he told me, he asked Coke’s social media experts to come up with “a big idea” that would be unique and turn consumers into brand marketers–what smart brand-owners must do today. The team delivered an idea called Expedition 206. It’s an online contest in which consumers vote, via Facebook and Twitter and other social networks, to elect a trio who will visit every country in the world where Coke sells its products. (Yes, Coke is in 206 countries.). Consumers have selected three finalist trios–who, if you look at the Expedition 206 site, you’ll see are from all around the world, literally. The winner will emerge in two weeks. Starting January 1, that trio will spend 365 days globetrotting “on a mission, quite simply, to find happiness,” as Tuggle puts it.

It’s a gimmick, but maybe a clever one in this new era when consumers, not companies, control public image.  “We have to move into a space where we let go,” as Tuggle says. “The world gets to experience the brand through the eyes of the consumer, not the company.”

Indeed, the consumer is now the chief marketing and communication officer.