Friday, February 6, 2009 Denny’s 1,600 chain restaurants across North America, Puerto Rico and Canada, were slammed for eight hours Tuesday with hungry patrons standing on sidewalks for nearly two hours to take advantage of the $5.99 “Grand Slam Breakfast” giveaway. Denny’s, a dining chain with annual revenue of about $900 million, has advertised in a TV commercial Sunday during the Super Bowl XLIII that it would give away its