Outgoing U.S. Defense Secretary Donald Rumsfeld thanks the 2/135th General Support Aviation Battalion Medical Evacuation unit at Balad Air Base for their service to the country during his surprise visit to Iraq December 9, 2006. Rumsfeld has made a trip to Iraq to offer his appreciation to the troops serving there, a Pentagon spokesman said on Saturday. Picture taken December 9, 2006. FOR EDITORIAL USE ONLY REUTERS/Cherie Thurlby/Defense Department/Handout (IRAQ)