Willie Williams and Joe O’Herlihy will be featured speakers at this year’s PLASA show, a lighting, audio, and stage engineering trade event. Williams and O’Herlihy will discuss their technical and creative involvement with U2 in a seminar titled “25 Years of U2’s Production.” The event, which will be held at Earl’s Court in London on 14 September, is open to the public (pre-register ticket price is