Presidential dance
President Barack Obama and U.S. Marine Sgt. Elidio Guillen wave to the crowd at the Commander in Chief's Ball Jan. 20, 2009 in downtown Washington, D.C. More than 5,000 men and women in uniform are providing military ceremonial support to the presidential inauguration, a tradition dating back to George Washington's 1789 inauguration. (U.S. Air Force photo/Senior Airman Kathrine McDowell)