David Duncan makes his way through the heart of London’s retail district looking for candles—not just any candles, but those his own Atlanta company makes.

Duncan strolls down Oxford Street, ducking into showrooms that retailers have decked out with Christmas trees, tinsel, gold, and silver. He browses displays, picking up candles to give them a sniff. He chats with Louise Marley and Debra Pattinson about expanding the U.K. presence of his company, PaddyWax, which already has products in stores like Fenwick, Hoopers, and John Bell & Croyden, the 200-year-old official pharmacist to the English monarch.

Duncan talks with Marley and Pattinson of future opportunities. “We're looking at growing our brand…as well as some private-label brands,” he says. Duncan is a model of enthusiasm and optimism, despite the fact that the world is coming off the worst economic crisis in eight decades. He’s in London as part of a group of American entrepreneurs and small-business owners who want to expand beyond their home bases—way beyond.

“It’s all about opportunity,” says the 36-year-old Duncan.

Duncan is one of several entrepreneurs Portfolio.com will follow throughout 2010 as they seize opportunities in an economy that’s cautiously recovering. These men and women see light when others see gloom. They’re starting businesses. They’re expanding existing companies. They’re looking for new ventures.

Rich Sloan, founder of StartupNation, is of the mind that big opportunities for American small-business owners just might be outside the United States. “The idea is to expand your marketplace and opportunities by taking what you offer to entirely new markets, such as those beyond our borders,” says Sloan.

Duncan is already a believer. He was just out of college when he and his wife, Gretchen Hollingsworth, started PaddyWax 14 years ago. The two of them grew the business about as far as they could. But recently, Duncan says, “It was playing defense.”

That was until August, when Duncan and Hollingsworth sold a majority equity position of their company to private equity firm Designworks Investments, run by Joseph Moore. It was the equity firm’s first investment, and the infusion of capital and management expertise, says Duncan, has freed him to play some offense as chief operating officer of PaddyWax. That includes a beefed-up e-commerce strategy and expansion abroad.

“It increases every single day,” Duncan says of PaddyWax’s foreign prospects. To look at him as he works, to hear him talk, you get the sense of a man who loves what he’s doing. “By all standards, I live a charmed life,” he says.

Duncan’s enthusiasm is echoed by the handful of American entrepreneurs Portfolio.com is tracking, after a trip they took to the British capital courtesy of a contest run by British Airways. Here’s an introduction to the rest of the men and women who are trying to demonstrate that globalization can be small, personal, and rewarding. In the coming weeks, you’ll be able to track their progress with stories and blog posts.

Nicole Donnelly: ‘The Word of Mom’

Nicole Donnelly, 32, has been kicking into opportunity since she came up with a way to warm her baby daughter Sara’s legs. Now she’s looking for the next big thing.

Donnelly, a former competitive snowboarder, found herself married and with a child, living in Seattle. Her little girl suffered from allergies that caused diaper rash and made it impossible for her to wear a diaper at times.

So Donnelly cut the feet off a pair of her heavy skiing and snowboarding socks to keep her baby’s legs warm while Sara went bare-bottomed. And a business was born, BabyLegs—multicolored leg warmers for little ones.

When she founded the company in June 2005, Donnelly sold her BabyLegs close to home. The business took off, especially after she learned the tricks of e-commerce and started reaching out to an international audience. In its first year, BabyLegs’ revenue was $80,000. By the end of 2006, revenue had grown to $1.1 million. By 2008, it was just under $5 million.

Donnelly attributes her success to the community she built through her website and network of international distributors. Both reached out to a worldwide network of moms at home with their children. Now she’s looking to expand on that opportunity, and last month she visited London, Barcelona. and Amsterdam to lay building blocks for future business.