Just before the presentation of "Best Supporting Actress" the curtain that was supposed to open to reveal the presentation screens don't open. You can then hear a stagehand from backstage yell, "We're doing it. Steve open it!" (his voice was probably picked up through Hugh Jackman's lapel mic.) See more
Brad Pitt and Angelina Jolie ladies and gentlemen. I don't actually have a joke for them I'm just contractually obligated to mention their names five times during the show.