Could a U.S.-Cuba prisoner swap break the ice?

                                                                                                                                                                                                                                                                                                      Alan Gross, a U.S. government subcontractor imprisoned in Cuba for smuggling satellite equipment onto the island, is being held at Havana's Carlos J. Finlay Military Hospital.With peeling canary-yellow walls and hordes of people coming and going, the aging building doesn't look like a place where Cuba would hold its most valuable prisoner.  But police officers and soldiers surround the hospital. Inside, Cuban special forces guard the 65-year-old U.S. citizen, emotionally and physically frail and approaching his fifth year in solitary confinement. North of the Florida Straits, Gross' imprisonment is seen as the major impediment to better relations with Havana.