http://www.military-aerospace-technology.com/article.cfm?DocID=192
“Last summer, we got a request from ACC to carry a laser-guided bomb,” Price said. “We had never carried one before. It was another one of those quick-response things. We have responded to a lot of those since 9/11 and the war on terrorism.”
The B-52 thus tested the guided bomb unit (GBU)-12 on March 28 (2003) in conjunction with the Litening II targeting pod. Historically, only fighter jets have carried laser-guided bombs. However, the B-52 can carry the bombs internally and externally and carry the capacity of six or more fighters, Morris said. A bomber like the B-52 can loiter at a high altitude and stay on station longer than a fighter. As such, it can stay in the immediate area and engage emerging threats, whereas fighters typically have enough fuel to fly to their targets and back. The B-52 demonstrated that capability on April 7 when it targeted the Baghdad airport during Operation Iraqi Freedom.
GBU-12 loading on B-52 during operation Valiant Shield (2007)
http://www.andersen.af.mil/shared/media/photodb/photos/070806-F-5853M-214.JPG
http://www.andersen.af.mil/shared/media/document/AFD-070810-005.wmv
More hi-res here http://www.917wg.afrc.af.mil/news/story_media.asp?id=123064941