It's that time of year-when thoughts turn to dieting and losing those extra 10 pounds before summer. In the spirit of slimming down, many celebrities have donated autographed belts for an online charity auction to benefit America's Second Harvest, the nation's largest domestic hunger-relief organization. The celebrity belt auction, sponsored by Post Healthy Classic cereals, is part of the company's new "Cinch an Inch" healthy weight-loss campaign that advises dieters to use the notches on their belt as a guide toward slimming success. Between April 25 and May 7, fans can go to charityfolks.com to bid on belts donated by country stars including Naomi Judd, Martina McBride, Blake Shelton, Deana Carter, Bill Engvall, Larry the Cable Guy and Miranda Lambert. Other non-country celebs include Cameron Diaz, Donald Trump, Britney Spears and the American Idol judges, Paula Abdul, Simon Cowell and Randy Jackson.