In the follow-up to the record-breaking hit comedy The Hangover, Phil (Bradley Cooper), Stu (Ed Helms), Alan (Zach Galifianakis) and Doug (Justin Bartha) travel to exotic Thailand for Stu’s wedding. After the unforgettable bachelor party in Las Vegas, Stu is taking no chances and has opted for a safe, subdued pre-wedding brunch. However, things don’t always go as planned. What happens in Vegas may stay in Vegas, but what happens in Bangkok can’t even be imagined.

Deadline is reporting that actor Paul Giamatti has joined the cast of The Hangover 2. It isn’t clear what type of role Paul Giamatti may have in the sequel, although it’s said he will join the cast in Thailand in a few weeks. Former president Bill Clinton has also joined the Thailand set of The Hangover 2, for a brief cameo appearance, according to People. Bill Clinton is portraying himself in the comedy, which is currently filming in Bangkok.

Giamatti and former President Clinton are the latest newcomers to join the comedy sequel, Jamie Chung has also signed on as well. Liam Neeson also has a cameo in the movie, replacing controversial actor Mel Gibson as a tattoo artist.

Todd Phillips is directing The Hangover 2 from a script by Scot Armstrong. The sequel follows the gang, played by Bradley Cooper, Ed Helms, Zach Galifianakis, and Justin Bartha, as they take a boys’ trip to Thailand with a dangerous stop in Bangkok. Asian gangster Mr. Chow, played by Ken Jeong, will also return.

A few months ago it was reported that Mel Gibson was seeking a role in Mad Men. That has yet to go further than rumor, but we now know the actor will have at least one other comeback role first. The New York Post reveals that the troubled actor will be playing a Bangkok tattoo artist in The Hangover 2. Though it wasn’t clear if he would be playing himself as an actor hiding out in Thailand or if he would be playing a character not at all associated with his own public image, Gibson’s role will mirror what Mike Tyson’s role accomplished in the first movie. This could give his public persona a much-needed comedic boost.

An insider told The NY Post,

“It’s a done deal. Mel will make a cameo as a tattoo artist. Filming is taking place on the Warner Bros. lot, where a Bangkok set has been built, and Mel is expected to film his role in two weeks. Then the production moves to Thailand at the end of October.”

The Hangover 2 will follow the comedic adventures of Bradley Cooper, Zach Galifianakis, Ed Helms, and Justin Bartha as they head to Thailand for a ‘boys only’ trip. Things take a nasty turn in Bangkok, where they have another run-in with Asian gangster Mr. Chow, who will once again be played by Ken Jeong.

Some other details on the plot came about a few weeks ago, saying the above information as well as some added things related to the comedic tone and style this movie will have compared to the other one.

“It takes place in Bangkok and LA,” Phillips told Empire. “There’s gonna be some f**ked-up surprises. The three guys are back,” Phillips said. “Mr. Chow’s back too. More carnage, more eccentric gangster weirdness from Ken Jeong and the promise of a tiger encounter in its natural habitat. Sounds good to our ears. Phillips, meanwhile, can spot a hacked-out sequel when he sees one and is promising that The Hangover 2 won’t follow in less-than-illustrious footsteps. “I’m not delusional,” he said. “I know what I’m up against. I saw Meet The Fockers. But we’re aiming high. It’s called The Hangover Part Two, you know.”

We talked a little about Phillips’ next projects in our Zack Galifianakis article earlier this week and it seems as if he is set for Phillips’ other comedy Due Date.

Galifianakis will play one of the two leads in Due Date, an Alan R. Cohen and Alan Freedland script that was revised by Adam Sztykiel. In the comedy about fatherhood, an expectant dad and his unlikely travel companion (Galifianakis) race cross-country in hopes of making it home for the birth of his first child.

Warner Bros. hired Phillips and Scot Armstrong to begin writing The Hangover 2 right after early test scores left the studio optimistic that it had a winner.

The film has become WB’s biggest grossing comedy ever, trailing only Beverly Hills Cop ($234 million) in grosses for an R-rated comedy. Studio believes The Hangover will finish around $240 million to become the biggest domestic grossing comedy ever and the third highest grossing R-rated film ever, behind The Passion of the Christ and The Matrix Reloaded.

June 5 is the release date for this summer’s comedy The Hangover, starring Zach Galifiankis, Bradley Cooper and Ed Helms. However Warner Brothers is already moving forward with plans for a sequel to reunite the main cast as well as the director, Todd Phillips.

“In a multimillion-dollar commitment, Warner Bros. has set “The Hangover” director Todd Phillips to write a sequel with Scot Armstrong. The dealmaking comes two months before the first “Hangover” goes out through WB on June 5.”

The news isn’t terribly surprising as the film was very much talked about during ShoWest in Vegas this weekend as well as the trailer getting raves after premiering at the convention as well as in front of screenings for Fast and Furious.

I laughed hard every time I saw the trailer and would welcome a sequel but unlike Star Trek, comedies are a harder sell for sequels than sci-fi epics. How do you not recycle the same jokes or risk doing the same thing over again? That will be the looming question as the film premieres in June.