Tube supremo Tim O'Toole will step down after six years in the job. Although Mr O'Toole says he's doing it for personal reasons (he'll return to live with his family in the States), some claim the resignation has more acrimonious motives. Boris Johnson was quick to Tweet his eulogy: "Will miss Tim O Toole. Great man but transatlantic relations must surely be pretty tough. Good luck mate." His finest hour came in the aftermath of the 7 July terrorist attacks, when his 'steely nerves' (Ken Livingstone's words) helped get the system up and running again so soon after the tragedy. Breaking with 400 years of post-Galilean astronomy, Mr O'Toole lamented to the BBC that "London is the centre of the universe and leaving here is going to be painful." The search begins today for his replacement.