U.S. President Barack Obama (R), is joined by Mexico's President Felipe Calderon (C), and Canada's Prime Minister Stephen Harper as they pose for photographs before participating in a leader's trilateral meeting at the Cabanas Cultural Center in Guadalajara, while attending the North American Leader's Summit, August 10, 2009. Obama, Calderon, and Harper gather on Monday to present a united front to try to limit the spread of the H1N1 swine flu, but there is less unity on simmering trade issues. REUTERS/Larry Downing (MEXICO POLITICS)