What would it be like if Matthew McConaughey really got caught up in a hostage situation? Would Brad Pitt really be able to de-activate a bomb when the clock has ticked down to the last few seconds? Or would he just wet himself?

These are the humorous questions behind "Tropic Thunder," the high-profile 2008 action/comedy flick currently in its final days of filming. With a cast including Ben Stiller, Robert Downey Jr., Jack Black, and Matthew McConaughey (subbing in for Owen Wilson), it certainly has the pedigree to become a thunderous success. And if a rumored cameo comes together, the film could just cruise to classic status.

"It's about a bunch of movies stars, and a rapper/actor, who get cast in this Vietnam War movie and get sent over to Vietnam to make this film," grinned box-office heavyweight Ben Stiller, who directs and stars in the flick.

"[Their movie] is going over budget," he continued, "and the director is freaking out because they're not getting the reality [look] that they need. So he takes them off into the jungle, and the actors get stuck out in the jungle for real."

"I play a guy named Rob Slolom, who is the executive in charge of the movie within the movie 'Tropic Thunder,'" explained "Hot Rod" star Danny McBride, pointing to his mullet. "I get to rock this ... so it should be a good time."

"We also got to hang out in Kuai," added Bill Hader. "[Our characters are] shooting a big budget Vietnam movie, and then they get embroiled in a real civil war! But they think that it's just part of the movie."

Added McBride: "Me and Bill then save the day."

"Kind of," Hader teased. "But not really."

The one co-star that none of the Hawaiian "Tropic" guys will confirm, however, is the long-rumored cameo by a certain couch-jumping A-lister.

"I don't know what you're talking about," stonewalled Stiller.

Time will tell - but until then, at least we can look forward to a comedic redux of a 70's Vietnam classic. "The movie is a funny 'Apocalypse Now,'" Stiller said of the tone he's going for. " Oh, the horror!