Maureen Kelly made her debut in the makeup business at age 6, when she mixed shaving cream with cough syrup and got sticky rouge—along with a scolding. "My mother was ready to kill me," she says. Kelly didn't stop loving face paint, but she did decide, as an adult, that "makeup wasn't a viable career option."

It took a guy to change her mind. Kelly started Tarte cosmetics in 1999 at the urging of her husband, Mark Ludvigsen, a bond salesman. She was unsure about her work as a psychologist and, Kelly recalls, "Mark said life is too short" not to follow your dreams. He was more right than they knew. By 2001 Tarte was selling in high-end stores like Henri Bendel and Nordstrom. But that September Ludvigsen, 32, died in the attack on the World Trade Center. "He called and said he was fine and would call back in 10 minutes," says Kelly, 31. "I never heard from him again."

So grief-stricken she could barely get out of bed, Kelly pushed on to make the Manhattan-based Tarte a success. The, company is projecting S2.7 million in sales this year, with 5 percent of the net profit going to charities like Dress for Success, while fans of her fanciful products (feathered powder brushes) include Jennifer Garner, Ashley Judd and Britney Spears. Says the still-single Kelly: "It was Mark's and my dream—he believed in me. I didn't want to let him down."