Ashton Kutcher had the good fortune of looking like Steve Jobs' long-lost cousin, so transforming himself into the icon of innovation didn't take much. But it's amazing what the haircut, glasses and beard can do, right? Here are 20 more recent performances that made us do a double take.
For 2014's "Guardians of the Galaxy," Chris Pratt gave up beer for six months ... and wound up looking like this.
Matthew McConaughey lost nearly 40 pounds to portray a man diagnosed with HIV/AIDS in the December release "Dallas Buyers Club."
David O. Russell's December release "American Hustle" is set in the '70s, and part of the fun of the film is seeing Bradley Cooper's impressive perm.
Elizabeth Banks' comedic timing is as sharp as ever in "The Hunger Games," but her makeup job is a far cry from how we're used to seeing her.
Daniel Day-Lewis looked presidential enough to appear on currency in 2012's "Lincoln." The actor portrayed the 16th president so thoroughly, he won an Oscar.
In "Looper," Joseph Gordon-Levitt was made up to look more like his co-star, Bruce Willis.
Meryl Streep won a best actress Oscar for her portrayal of British Prime Minister Margaret Thatcher in 2011's "The Iron Lady," and so did members of the makeup team behind her altered appearance. They told Entertainment Weekly they pulled it off by working around Streep's natural facial elements, such as her eyebrows.
50 Cent had fans worried that he was truly ill when images surfaced of his role as a man suffering from cancer in "All Things Fall Apart."
While some actors have gotten extremely thin to play their characters, Jared Leto went in the other direction for "Chapter 27," packing on 60 pounds to portray Mark David Chapman.
Even if you don't remember 2008's "Tropic Thunder," you likely recall that Robert Downey Jr. was in blackface for his role. The controversial makeup choice was reflective of the lengths that Downey's method actor character, Kirk Lazarus, would go to portray a Vietnam War sergeant who was initially written as African-American.
Charlize Theron's transformation into serial killer Aileen Wuomos was amazing -- she also won the best actress Oscar for 2003's "Monster." Gaining weight not only helped Theron fit the part, but she also wore makeup to create a less perfect complexion and a set of crooked, yellowed teeth.
Nicole Kidman nabbed a best actress Oscar for her portrayal of Virginia Woolf in 2002's "The Hours." But the makeup job that changed her appearance -- aided greatly by a prosthetic nose that stirred debate -- didn't receive a nod.
For his role as a man who aged in reverse in "The Curious Case of Benjamin Button," Brad Pitt "had to endure the most complicated and time-consuming makeup effects," sometimes spending five hours at a time in the makeup chair, producer Frank Marshall told Variety in 2008.
Christian Bale's disturbingly gaunt frame in "The Machinist" is a legendary tale of going all out for a character. The actor famously dropped 63 pounds for the part by sticking to a diet of coffee, cigarettes and an apple a day.
Heath Ledger's Joker was thrillingly unhinged in 2008's "The Dark Knight," and the makeup job was part of the package. Both the actor and the makeup team were nominated for Oscars, but it was Ledger who was honored posthumously with the award.
When she landed the part of Lisbeth Salander in 2011's "The Girl With the Dragon Tattoo," fresh-faced Rooney Mara got a severe haircut in an inky hue, bleached her brows and pierced her nose, lip, eyebrow and nipple.
Critics heaped praise on Marion Cotillard's award-winning portrayal of French icon Edith Piaf in 2007's "La Vie en Rose." The physical part of her transformation into Piaf took patience, with Cotillard's role demanding five hours in a makeup chair.
Eddie Murphy has a knack for portraying multiple characters in the same film, and in 1988's "Coming to America," he played Prince Akeem and comedic barbershop gentleman Saul (pictured, right) among others. Makeup artist Rick Baker earned an Oscar nod for his work.
Julianne Moore was tasked with convincingly portraying Sarah Palin in HBO's 2012 movie "Game Change" and implicit in doing so was looking the part. Moore pulled it off, picking up an Emmy in the process. Among those she thanked? Her hair and makeup team, of course.
The makeover for Eric Stoltz in 1985's "Mask" was astounding as Stoltz portrayed "Rocky" Dennis, a boy trying to live a normal life with the disorder lionitis. The transformation picked up an Oscar for best makeup.
- Ashton Kutcher is portraying Steve Jobs in this weekend's biopic 'jOBS'
- The actor committed himself to the role, learning Jobs' mannerisms and his diet
- The latter aspect of the character put Kutcher in the hospital
- He says it was worth it to learn how disciplined Jobs was
(CNN) -- Matthew McConaughey lost 40 pounds for December's "Dallas Buyers Club," and Matt Damon worked out for four hours a day to get ripped for "Elysium."
Ashton Kutcher, meanwhile, wanted so badly to get the role of innovation icon Steve Jobs right, he put himself in the hospital.
The 35-year-old actor became a fruitarian while filming Steve Jobs biopic, "jOBS," in an attempt to "understand some of his discipline," Kutcher explained to CNN.
He picked up a book Jobs once read by Arnold Ehret called "Mucusless Diet Healing System" and began to eat nothing but fruit, shedding 15 to 18 pounds in the process, according to "jOBS" director Joshua Michael Stern.
"(Jobs) was a really disciplined guy in a lot of ways, around his work and his life and his relationships and his products," Kutcher said. "And part of going on the diet was just to try to get an understanding of that. I didn't like it very much. It was really painful, ultimately. But it was really worth it, 'cause I think I gained a level of empathy towards that kind of discipline and focus that I don't think I could have played the role without."
Arriving Friday, "jOBS" traces Steve Jobs' ascendance from college dropout to globally influential creator and will recount his founding of Apple along with Steve Wozniak (played by Josh Gad).
As one of the more tech-savvy stars in Hollywood, Kutcher was initially nervous to portray someone he calls his "hero."
"I admire him, and I admire his work," Kutcher told CNN. "The scariest thing for me was that I wanted ... people to see my portrayal of him and see it as a portrayal that was honoring him and being honest about some of the flaws that he had. That was really a daunting task."
Of course, Kutcher came to the part with a genetic advantage: The actor, who also stars on CBS' "Two and a Half Men," shares a resemblance to the late Jobs, who died in October 2011. But according to director Stern, Kutcher didn't try to rely on just his looks.
"Ashton walked into the first meeting already channeling Steve Jobs," he told CNN. "He had the mannerisms; he'd studied hundreds of hours. He knew from that first meeting that I needed to take away evidence that he could play the part."
Kutcher's total immersion into the character was so complete that Stern walked away from the actor with newfound respect. "He studied the guy; he lived in his skin every day, which wasn't the easiest place to live, and I really respect him quite a bit. He gave everything he had, and more than anything I knew that this role was important to him. And when something's important to you no matter what you do, you're going to give it everything you have."
Despite those efforts, "jOBS" has faced criticism ahead of its release date, from Kutcher's casting on down.
The biopic was originally slated to bow in April, but was bumped back to August reportedly so the studio could have a longer marketing push. Reviews, thus far, have been mixed, and then there are those questioning its timing.
Kutcher says that when he received the script, which was already a work in progress when Jobs died, that he did have that "immediate concern."
"I know that there were some people that were close to him who didn't want a movie to be made this soon," he said, but because "I have friends that actually know him, I felt ... I could at least protect his legacy somewhat by playing (the part), and I knew I would dedicate myself to making it as good as I could."
When you make as great of an impact on the world as Steve Jobs did, that story's going to be told eventually, no matter what. "I would rather have it get told before the tales about him get too tall and while we could tell an honest story," Kutcher continued. "A lot of times, someone passes away and all of a sudden the stories become these fictional tellings of what happened. I think this film is as close to true as we could find."
At this year's Teen Choice Awards, Kutcher addressed the young crowd in a Jobs-ian motivational moment. He told fans "sexy is smart," "opportunities look a whole lot like work" and closed his speech by saying, "build a life; don't live one."
CNN's Carolyn Sung and Jane Caffrey contributed to this report.
