Some of the world's wealthiest men are ready for their Hollywood close-ups.

The highly anticipated big-screen version of the HBO series "Entourage" hits the big screen this weekend, offering an insider look at the business of Hollywood. Vincent Chase (Adrian Grenier), E (Kevin Connolly), Johnny Drama (Kevin Dillon) and Turtle (Jerry Ferrara) are still together, this time behind the scenes as aspiring movie directors and producers. Former super agent Ari Gold (Jeremy Piven) also makes his triumphant return as the newly named head honcho of a studio trying to get a film onto the big-screen.

Rounding out the cast is Texas billionaire (Billy Bob Thornton), and his meddling son Travis (Haley Joel Osment), playing deep-pocketed investors bankrolling and thwarting Team Entourage every chance they get.

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Perhaps equally as noteworthy as the returning stars is a roster of surprise cameos featured throughout the film, many of them real-life business leaders. One in particular is a celebrity in his own right.

Berkshire Hathaway Chairman and CEO Warren Buffett appears midway through the film, as he crosses paths with Ari Gold. Buffett's cameo is brief, but he does manage to toss off a few memorable one-liners before zipping off in his golf cart across the Warner Brothers studio backlot.

Buffett, of course, is no stranger to celebrity. He's famous for hobnobbing with athletes such as basketball star LeBron James and boxer Floyd "Money" Mayweather Jr.

In the film, Buffett is joined by several other entrepreneurs, most notably Dallas Mavericks owner and "Shark Tank" co-host Mark Cuban. The outspoken billionaire is featured in a crowd during a raucous Malibu beach party scene.

In an email to CNBC's "Power Lunch" this week, Cuban recounted his on-set experience.

"It was a blast," Cuban said. "It was great to see everyone back together again, and I loved the way the movie turned out." In 2011, Cuban made his first appearance on the televised version of "Entourage," talking about the tequila business with Turtle.

New York Giants co-owner and film producer Steve Tisch has a brief speaking part, which comes during a pivotal boardroom showdown. Tisch's previous movie producer credits include "Forrest Gump" and "American History X."

The part in the "Entourage" movie "was a return for me. I was in the TV series," Tisch told CNBC in an interview. "Now I have something in common with Warren Buffett! We are both movie stars," he joked. "It's great to do a project like this with friends."

The movie's writer and director, Doug Ellin, explains how the cameos all came together: "The goal of 'Entourage' is and has always been wish fulfillment, the ultimate fantasy," Ellin said.

"No matter where you are in the world, say you're sitting somewhere in the freezing cold, you can go to the theater and look at what's happening on the screen and say, 'Wow, I really want to go there.' "

Behind the scenes, legendary Wall Street investor Steven Mnuchin took a lead role as real-life producer of Entourage. "I am extremely proud of what ... Doug Ellin and his team did to convert the TV franchise to film," he told CNBC in an interview.

Mnuchin, co-founder and chairman of Dune Capital Management, is best known for leading the private buyout of IndyMac. He has an equally successful track record as film financier on blockbuster hits including "Avatar," "The Devil Wears Prada," "The Life of Pi," "Gravity" and "The Lego Movie."

So how does Mnuchin make such a smooth transition between Wall Street and Hollywood?

"My criteria is simple. It's all about content and a deep portfolio," he said. "Investing in any one film is always a risky proposition, but if you can invest in enough films, and create a large library of content, then long-term, that content becomes more and more valuable. You need great movies to stream on. "

Mnuchin's future projects include the forthcoming DC Comics blockbuster, "Batman vs. Superman."