"Bon anniversaire (happy birthday), Cannes!" shouted U2 frontman Bono, before the band rocked the steps of the Palais with an impromptu mini-concert to introduce a preview of U2 3D, a feels-like-you're-there concert flick. The boys from Ireland gave the crowd a thrill, performing "Vertigo" and "Where the Streets Have No Name," a welcome alternative to the usual pre-show movie trailers.