AUTOGRAPH STOP U.S. Navy Adm. Mike Mullen, chairman of the Joint Chiefs of Staff, autographs a football after the USO holiday tour on Bagram Airfield, Afghanistan, Dec.15, 2010. Mullen and his wife, Deborah, are hosting the tour featuring comedians Robin Williams, Lewis Black and Kathleen Madigan, Tour de France champion Lance Armstrong, and country musicians Kix Brooks and Bob Dipiero in the Central Command area of responsibility. SHARE: Download: Full Size (0.07 MB) Credit: VIRIN: 957257-Z-IPO45-509.jpg Photo Gallery