President Obama returns a salute prior to boarding Air Force One at Andrews Air Force Base, Md., Friday, June 25, 2010, prior to traveling to Canada for the G-20 summit. (AP Photo/Charles Dharapak)

Photo by: Charles Dharapak

President Obama returns a salute prior to boarding Air Force One at Andrews Air Force Base, Md., Friday, June 25, 2010, prior to traveling to Canada for the G-20 summit. (AP Photo/Charles Dharapak)