To call Dan Nainan frugal is an understatement. He lives in New York City, home to the world’s largest public transit system, but insists on walking. Everywhere. Sometimes for miles on end. When he travels he prefers to couch-surf and don’t be fooled if you see him at Starbucks. He’s not ordering any lattes. He just stays for the free Wi-Fi. “There are two ways to become a millionaire. You either make a lot of money or be a frugal person,” says Nainan.