Ashton Kutcher as Steve Jobs
As well as the (admittedly quite freaky) physical resemblance, Ashton Kutcher is perhaps the most qualified actor around to play Steve Jobs. After all, they're both technological visionaries: Jobs being the brains behind Pixar, the Mac, the iPod, iPad and iPhone, and Kutcher being an early investor in startups such as Skype, Airbnb and Foursquare. What's more, Jobs was known for his obsessive perfectionism and ability to convince the public of a product's desirability. Having been the host of Punk'd and the star of Dude, Where's My Car, Kutcher also ... no, I don't know where I'm going with this one.
Jesse Eisenberg as Mark Zuckerberg

Jesse Eisenberg only shares a handful of obvious traits with Mark Zuckerberg – like age, hair colour and the last syllable of his surname – but that didn't stop him from doing a bang-up job of playing the Facebook founder in The Social Network. Eisenberg perfectly captured Zuckerberg's short-fuse nervous energy and jumpy intellectualism. Perhaps it's because they both share humble beginnings; Zuckerberg was raised in a small upstate New York village and Eisenberg starring in Lightning: Fire From the Sky, a terrible TV movie about lightning, which came in the form of fire from the sky.
Justin Timberlake as Sean Parker

Napster's Sean Parker was often described as a "rock star", so who better to play him in The Social Network than frizzy-haired pop crooner Justin Timberlake? Timberlake absolutely nailed Parker in the movie, provided that the real-life Parker is a swaggering tool who lives his life like it's the world's worst Puff Daddy video. He may not actually be like that, but let's assume he is. After all, Justin Timberlake is the star of In Time, so we can't really doubt his acting credentials.
Alexander Armstrong as Clive Sinclair

In 2009, Alexander Armstrong starred in BBC4's Micro Men, a biopic of Clive Sinclair, the inventor of the pocket calculator. Painfully conspicuous slaphead wig aside, the casting was inspired. Armstrong managed to channel Sinclair's blind devotion, volcanic temper and awkwardness around women magnificently. Perhaps he was able to access the mindset of a compulsive attention-seeker such as Sinclair so easily because of his own determination to present every single television programme that has ever been made.
Martin Freeman as Chris Curry

Meanwhile, the more mild-mannered Martin Freeman played Acorn co-founder Chris Curry in Micro Men. Curry, in a sense, was an amalgamation of every character that Freeman has ever played. Like John Watson, he's a quiet pragmatist sidelined by a more charismatic partner. Like Tim from The Office, he enjoys a flirtation with a secretary and aspires to a better future that exists just out of his reach. And like Bilbo Baggins, his prosthetic eyebrows are incredibly off-putting. Perfect casting, really.
Bill Gates in The Simpsons
Although Bill Gates made a fleeting appearance in The Social Network (played by a professional lookalike), his greatest onscreen moment came in The Simpsons episode Das Bus. Voiced by Hank Azaria – who plays Moe, Apu and Comic Book Guy, among others – Gates's appearance is brief and incendiary. He marches into the Simpson household and acquires Homer's startup by ordering some hired goons to smash up his office. Is this realistic? Would Bill Gates ever make a business decision as bad as acquiring Homer's Compu-Global-Hyper-Mega-Net in real life? You only have to look at the infamous Zune to know that the answer is probably yes.
Richard Ayoade as Moss

He may not be based on anyone from real life, but Moss from The IT Crowd is just about a perfect blend of any number of famous nerds. He's got the glasses of Steve Jobs, the uniform of Bill Gates, the slightly inept never-say-die attitude of Clive Sinclair and the vast haircut of Steve Wozniak in the 1970s, although back then Wozniak wore it as a beard.