You'd think it would be tricky to get the normally po-faced breed of A-listers to mercilessly take the piss out of themselves on the big screen. But these days Hollywood greats are tripping over themselves to don unflattering clothes, dance like chumps and lampoon their personal life in the hope of showing the public that they do actually possess a sense of humour. As a PR exercise, it's genius. Make us laugh hard enough and we might even forgive the Scientology stuff (or something). We still haven't recovered from Tom Cruise's brilliant turn as film exec Les Grossman in Ben Stiller's Tropic Thunder, and now the Coen Brothers' Burn After Reading delivers a bumper load of celeb cameos from George Clooney, John Malkovich and Brad Pitt. Of the three, it's Brad that delivers the funniest moments of the film. The Angelina years have rebranded Brad as a sensitive, serious dad-type, so it's a treat to see him as a gum-chewing, iPod-bopping gym bunny. But much as we love Brad, for us it's vintage Cruise that wins the battle of the celeb cameos. Watch him here in Magnolia. What do you reckon?