Double Take: Best Young-To-Old Casting

Taking on a universally beloved and time-tested character is no easy feat, but Zachary Quinto made a career for himself when he played a young Spock in the 2009 'Star Trek' reboot. His Spock was brilliant, humorous, complicated, and ultimately Leonard Nimoy-approved – Nimoy himself had casting approval, and thought his younger counterpart was simply terrific.

Casting the gorgeous, sultry Mila Kunis as a younger version of the gorgeous, sultry Angelina Jolie might be a no-brainer in 2012, but it was a stroke of genius for the 1998 film 'Gia.' Kunis played the 11-year-old version of the drugged up, lesbian model who died of AIDS in 1986. 

The late, great River Phoenix was so convincing as Harrison Ford's son in the 1986 film 'The Mosquito Coast' that he was a shoo-in to play a 13-year-old Indy in 'Indiana Jones and the Last Crusade.' The actors developed a tight bond, and Ford even said he loved Phoenix like a son after his untimely death.

The 1995 coming-of-age film 'Now and Then' may not go down in the history books, but casting Gaby Hoffmann as a younger Demi Moore was a much better decision than, say, Christina Ricci as a younger Rosie O'Donnell. 

Okay, no one actually believes that Matthew Perry *looked* like pretty boy Zac Efron in his high school days. Still, Efron nailed Perry's likability and charisma, and we even imagined Perry's adult voice as Efron (creepily) tried to win back his still-adult wife in the 'Freaky Friday'/'13 Going on 30'/'Big' knock-off '17 Again.'

From 1977-1983, Alec Guinness turned the Jedi Master Obi-Wan Kenobi into one of cinema's greatest and most beloved heroes, with or without a corporeal body. So when George Lucas released the first prequel to the original 'Star Wars' trilogy in 1999, Ewan McGregor had big boots to fill. Luckily, McGregor nailed Guinness' accent and mannerisms — he graciously honored the original films, even when the scripts betrayed him.

As a 13-year-old girl, Briony Tallis (Saoirse Ronan) did some very, very bad things. Vanessa Redgrave was the perfect choice to play the elderly version of the character, who spent the rest of her life trying to atone for her astonishingly devastating sins — not only do the two actresses share the same piercing blue eyes, they worked together to keep their speech and mannerisms in check.

It's hard to say who was scarier: Jasper Newell as the Damien-esque six-year-old Kevin Khatchadourian, or Ezra Miller as his murderous teenage counterpart. Both Kevins were wickedly detached, manipulative, vicious, and ultimately haunting. Yeah, they really should have talked about Kevin.

With all of this talk about Josh Brolin in 'MIB3', it's only fair to pay homage to that other film that featured a main character traveling back to the '60s to pair up with a younger version of his colleague: 1999's 'Austin Powers: The Spy Who Shagged Me.' Rob Lowe's take on Robert Wagner's Number Two probably didn't require many intense study sessions, but he nailed his older counterpart's suave demeanor and notable business savvy. And the hair — oh, the hair. 

Does anyone else expect Tom Hanks to look exactly like Dabbs Greer when he grows up? Hanks' Paul Edgecomb faced a soul-crushing decision as a young man, and Greer is haunting as the (much) older, world-weary version of the eternally tortured character.