[img]http://d.yimg.com/a/p/afp/20100412/capt.photo_1271018552228-5-0.jpg?x=88&y=130&q=85&sig=2e994YyduScnH3gKOyDoLw--[/img]AP - President Barack Obama and presidents, prime ministers and other top officials from 47 countries start work Monday on a battle plan to keep nuclear weapons out of terrorist hands.