PHILADELPHIA -- Dan McSweeney has a few ideas for saving the United States. That would be the SS United States -- the fastest ocean liner in the world. Bigger than the Titanic and fast enough to water-ski behind, she's a steamship so sophisticated, her capabilities remained a Cold War secret for decades. She transported royalty and starlets. Her crew served frog legs in first class. Before the dawn of the jet age, the SS United States was the Concorde of her era. 'Big U' in Big Trouble? Admirers call her the "Big U." Today, she could be in big trouble....