Four-week games organized by New York-based DietBet, have been run at more than 500 companies, allotting cash prizes to any participant who sheds 4% of body weight. Chief executive Jamie Rosen says 90% of players slim down, averaging a 5.4-pound loss. Other employers run ad hoc contests, usually modeled after NBC-TV's winner-take-all 'Biggest Loser' series. Read the full article.

It's a great accountability system,' says personal trainer Tony Pino, who work at Platinum Gym in Sanford. Now that he knows about DietBet, he says he's going to encourage his clients to use it. When you have something to shoot for and then you have a group of other people shooting for the same goal or heading in the same direction, that gets momentum,' Pino said. Read the full article.

This social dieting game puts your money where your mouth is. Create a game with friends, set the bet amount, and the first person to lose 4% of their starting weight wins the pot. The more people who play, the bigger the pay. You can also join in existing games. Read the full article.

New websites and apps known as weight loss wager programs are encouraging dieters to gamble their way to a leaner figure, betting on whether they can shed unwanted pounds. TODAY's Erica Hill reports and Jamie Rosen of DietBet.com shows how the program changed the lives of five employees. Read the full article.

DietBet.com wants to help you make money while dieting. You can set up a challenge of your own or join another group. The competition lasts four weeks and the person who loses 4% of their bodyweight during that time wins. Celebrity trainers, gyms, HR managers, charities and others already have challenges set up on the site. DietBet is available for iPhone, iPod Touch and iPad. Read the full article.