Call that an armoured car? The entourage of General Aladeen, Supreme Leader of the Republic of Wadiya arrives at a public ceremony in the centre of London. In other words, actor Sacha Baron Cohen and crew turn up for the premiere of The Dictator at the Royal Festival HallPhotograph: Jon Furniss/WireImageBaron Cohen steps out and fondles his golden gun in front of the crowds. Can't say the presidential guard look too entranced; the ones at the back are practically asleep. Wake up, this man could be assassinated at any minute!Photograph: Tal Cohen/AFP/Getty ImagesOh look, a lone protester has broken through the police lines, but Baron Cohen bravely takes him on. As the protester in question is clearly Harrods owner Mohamed Al Fayed, I don't suppose anyone's life is in real dangerPhotograph: Fred Duval/Getty ImagesHere's proper talent: Ben Stiller looking all director-y on the set of The Secret Life of Walter Mitty in New York. Stiller's actually got a great record as a director: Reality Bites, The Cable Guy, Zoolander, Tropic Thunder; the guy deserves a medalPhotograph: Bobby Bank/WireImageA smart bit of promo from the people behind low-budget UK indie The Silver Goat – the 'first ever' iPad film premiere, so they say, in a London bus shelter. Here's the cast; lead Alexa Brown is the one in the middlePhotograph: Sam Pearce/www.square-image.co.ukHere's how to do a premiere properly. Gossip-mag staple Rihanna is snapped by photographers as she makes her way on Thursday into the US premiere of Battleship, her first big Hollywood number. Wonder why she gets so much attentionPhotograph: Danny Moloshok/REUTERSWhen you're a Hollywood big shot, you need at least three people to help you get through a door. Bruce Willis, on the set of Die Hard 5 (aka A Good Day to Die Hard) in the Hungarian capital Budapest, takes pampering to a whole new level. So that's why he's got that smirk goingPhotograph: Bea Kallos/APMore premiere action: Josh Brolin, Will Smith and Tommy Lee Jones make an entrance for Men in Black 3 in Tokyo. Smith's suit wins by a nosePhotograph: Rex Features/AfloHere's how to really impress. Jack Black and Kyle Gass, in their guise as 'funny' rockers Tenacious D, play for actual normal people on a street. Don't think they were busking as such; they were apparently filming a show for the website VEVO. Never mind, everyone looks happy – apart from that kid, who just looks confused Photograph: Angela Weiss/WireImageHow to get a grant, part 47. Polish animator Zbigniew Rybczynski gets all knightly with Neelie Kroes, European Commission vice-president in charge of the Digital Agenda, at an EC meeting in Brussels. Absolutely shamelessPhotograph: Olivier Hoslet/EPAHelena Bonham Carter has a good go at emulating her poster image at the Dark Shadows premiere in London's Leicester Square on Wednesday. Nice try – but, duh, it's the wrong handPhotograph: Jon Furniss/WireImage