It was a sight that would have made even the taciturn Mr. Darcy blush. Keira Knightley briefly channeled Tara Reid at Thursday's New York premiere of "Pride and Prejudice" when her strapless scarlet gown succumbed to gravity as she posed for photographers. As the New York Daily News so vividly tells it, "Just moments after a flack proudly informed the press that [Keira] was wearing a Calvin Klein dress that had been made just for her, a shapely British bosom emerged into the night air." The actress, 20, was apparently oblivious to her drooping décolletage, with an eyewitness telling the London Daily Mail, "She didn't look like she had realized what was going on and no one pointed it out to her." And yes, we know where you can see snaps of her badly behaving bodice, and no, we're not gonna tell you.