Britain's Queen Elizabeth visited Reuters' new global headquarters in London's Canary Wharf on Tuesday -- and then sent a simulated despatch to mark the official opening of the building. After touring the newsroom, meeting photographers and being introduced to clients, she promptly "filed" a story about the opening by pressing a button. When she hit the button, the story appeared on a large screen outside the building in London's new financial district on the site of former shipping wharves. Editors then sent the story to subscribers. Staff from six Reuters buildings around London moved into the new global headquarters in July and August with 2,500 working in an open plan design.