Thomas Jane recently admitted that he turned tricks on Santa Monica Boulevard when he was a struggling young actor. This stint as a male prostitute probably gave him the edge when auditioning for his current role as a male prostitute on the HBO series Hung.

This made us wonder about what other films and roles might have been preceded with some distasteful or otherwise unpleasant preparation. As it turns out, the list is pretty daunting. We take for granted that actors must really submerse themselves in roles that require them to pretend to know how to fire a rifle or be sexually attracted to Jack Black.

Here's our take on one of the darker sides of Hollywood.

9. Ashley C. Williams, Ashlynn Yennie, and Akihiro Kitamura – Human Centipede

All actors playing characters that were part of the centipede had to complete a rigorous three-week camp in Morocco at which they had to complete countless trust exercises, centipede observation, and pooping in each others’ mouths.

Said one actor, who requested not to be identified, “It was the best three weeks of my life.”

8. Brad PittMoneyball

In order to “sell” the role of real-life baseball GM Billy Beane, Brad Pitt thought it best that he train himself to be able to discuss baseball without instantly passing out due to boredom. It’s Hollywood’s worst-kept secret that he developed a pretty serious crystal meth habit just so he could stay awake to read lines about OBP, slugging percentages, and balks.

Halfway through filming, he learned a trick from Bob Costas, who inserted a tack into Pitt’s right shoe, instructing him to step down on it, causing enough pain to keep the user alert while engaged in a conversation about pennant races at the All-Star break. It is supposedly the same trick that Freddie Prinze Jr. used while filming Summer Catch.

7. Leonardo DiCaprio/Joseph Gordon-Levitt – Inception

This was a more scientific undertaking than it was a psychological problem. Whenever DiCaprio and Gordon-Levitt were in character, explaining the “levels” of dreams to other characters onscreen, their ears and eyes would begin hemorrhaging blood. It was never enough that Christopher Nolan or the crew would fear for their safety, but it was enough to require frequent costume and makeup changes.

Initially, Nolan spent the better part of nine months putting the cast before dream experts and physics professors to explain the plot, but when even the academics’ eyes started to spew blood, Nolan cut his losses and simply cleared out all the blood in post-production, courtesy of Industrial Light and Magic.

6. Kristen Bell/Josh Duhamel – When In Rome

In order to convincingly portray two Americans traveling abroad, both leads had to take obnoxious lessons that they learned by simply watching tourists in line at the Louvre in Paris. Among the things they learned:

  • How to send back unfamiliar food with disdain

  • How to disregard all local culture in order to find a familiar Irish pub or Hard Rock Café so that they can drink Coors Light

  • How to communicate with non-English speakers by speaking English loudly and slowly

  • How to pick the right NFL jersey to wear in the local country’s house of worship

Amazingly, Bell and Duhamel couldn’t even get their house in order to be believably obnoxious, so they spend the whole film being charming and courteous, which isn’t believable at all.

5. Katherine HeiglKnocked Up

Preparing her role for a woman in a relationship with a fat schlub, Ms. Heigl went on a private cruise with Kevin James and Adam Sandler’s wives, where they got drunk off white wine and talked about the logistical difficulties of getting aroused to a man in sweatpants wearing a novelty t-shirt.

Apparently, there was a lot of crying.

4. George ClooneyUp In The Air

As someone who has only flown private for the past 15 years or so, Clooney had to prepare for his role as an unencumbered frequent flier by reading hundreds of in-flight magazines, studying back issues of SkyMall, and practicing rolling his eyes and muttering under his breath when he learns that his flight is delayed.

Always one to over-prepare for a role, Clooney spent two weeks living in the Chicago O’Hare Admirals Club where he learned how to blandly ask about last night’s football game. He also spent fifteen weeks eating lunch at Chili’s Too, where he was taught the intricacies of making awkward advances towards female travelers while sipping an Electric Lemonade.

3. Daniel Day-LewisThere Will Be Blood

So that he could hone his chops for the role of soulless oilman Daniel Plainview, Day-Lewis spent the year before that just being a total dick to everyone he knew. He’s such a method actor that it was really the only way. He went to restaurants and tipped 11%, would bring his girlfriend to poker night, and would get into his car parked at crowded malls, then take forever to back out of his space for the waiting car.

With that kind of preparation, it’s no wonder he got the Oscar.

2. Matt DamonThe Bourne Identity

In preparation for the iconic franchise kickstarted by helmer Doug Liman, Matt Damon spent two weeks running around crowded train stations, hiding behind columns, and beating the hell out of people using only rolled-up magazines.

He also spent a little over six years practicing getting the SIM cards out of various cell phones really, really quickly.

1. Nicholas Cage, et al – Gone In 60 Seconds

With an eye on detail to the specifics of the car theft subculture, the producers behind Gone in 60 Seconds wouldn’t let any actor join the cast until they had stolen five cars. Nicholas Cage famously placed himself outside Morton’s during the Vanity Fair Oscar party, stealing Helen Mirren’s Lamborghini and Jonathan Lipnicki’s Escalade.

It’s also rumored, but not proven, that Giovanni Ribisi had to be taught how to drive stick for the role. Seriously. How lame is that?

Since you’ve already come this far, you might as well take a look at this gallery of sexy Scarlett Johansson photos.

Or, if you don't like girls, check out 9 Marvel Heroes You Won’t See In The Avengers.