LONDON: The mayor is right on one count: London's Olympic volunteers will be impossible to miss. London Mayor Boris Johnson introduced the vanguard of his volunteer team for the London Olympics on Friday, showing off their purple uniforms and matching trilby hats. The eye-catching colors will be worn by 8,000 people who have volunteered to help tourists find their way around the sprawling city during the games. Johnson, whose unruly mop of hair would challenge any trilby, says the goal is to make the ambassadors "highly visible" and of course helpful. The volunteers will be stationed at 43 locations, including landmarks and key areas such as Heathrow Airport, Trafalgar Square, Oxford Street and Wimbledon. The games start July 27 and end Aug. 12.