Wish I'd thought of this - way to get a cheap flight!

David Phillips, a civil engineer at UC-Davis, has become a cult hero in the obsessive subculture of people who collect frequent-flier miles by converting $3,150 worth of pudding into 1.2 million miles. Oh, yeah-he's also going to claim an $815 tax write-off.
Last May, Phillips was pushing his shopping cart down the frozen-food aisle of his local supermarket when a promotion on a Healthy Choice frozen entrée caught his eye: He could earn 500 miles for every 10 Universal Product Codes (bar codes) from Healthy Choice products he sent to the company by Dec 31. Even better: Any Healthy Choice bar codes mailed by the end of the month would rack up double the mileage, or 1,000 miles for every 10 labels....

http://www.snopes.com/business/deals/pudding.asp

I don't think there will ever be a promotion like this again, but what a great story!