So Julia Roberts was paid $500,000 a minute for her six-minute turn in Valentine's Day. Surprised? You shouldn't be. Roberts has form when it comes to the cameo: she cut her teeth in Robert Altman's The Player, then turned in cameos as a bed-hopping reporter in Prêt-à-Porter and an especially larky (read: grating) one as herself in Ocean's 12. The cameo is the ideal way to make some serious cash on the sly. After all, there's no appearance more special than one that is actually labelled a special appearance. Or, better still, not labelled at all. Here are five other repeat bit-part offenders.
Marlon Brando
The big daddy of the cameo demanded top billing, $3.7m (£2.4m) upfront and a hefty profit share (current total: $14m) for his 10-minute role as the Man of Steel Snr in Superman. He also bagged top billing and an Oscar for his (essentially supporting) role in The Godfather; then repeated the trick for Apocalypse Now – $1m upfront in exchange for 15 minutes of screen time.
Orson Welles
There's a weird dignity to his studio head in 1979's The Muppet Movie ("Prepare the standard 'Rich and Famous' contract for Kermit the Frog and Company") and something sonorous about his last ever role, as the voice of Unicron in the 1985 Transformers cartoon. Welles not only hated it, but, when quizzed, couldn't remember his character's name – just that it was "a big toy who attacks a bunch of smaller toys".
Judi Dench
An Oscar for nine minutes of gummy cackling in Shakespeare in Love. But there's a less respectable cameo in the cupboard. Check out Dench's floaty-robed turn as Aereon, an "envoy from the Elemental race", opposite Vin Diesel in The Chronicles of Riddick.
Arnold Schwarzenegger
He just can't help himself: Welcome to the Jungle, Feed, Dave, The Kid & I, plus he's contributed "CGI facials" to Terminator Salvation, voiced a tough Hummer called Sven in Cars, and – lest you thought he didn't have range – played a lecherous Turkish prince in Around The World In 80 Days. Soon to be seen, fleetingly, in Sly Stallone's The Expendables. Will Arnie return to the big screen after he's left politics? Just try and stop him.
Tom Cruise
These days, everyone hates a Tom Cruise film. But everyone loves a film in which Cruise takes a self-mocking cameo. His three minutes of ghastly dancing as a studio exec in Tropic Thunder was deemed to be the best thing he had done in years – well, since his turn in Austin Powers in Goldmember, which was the best thing he'd done since his one minute as a grubby cowboy in Young Guns.
• This article was amended on 17 February 2010. The original said that Orson Welles was the voice of Optimus Prime in the 1985 Transformers cartoon. This has been corrected.
