Ben Stiller writes, directs and stars in this very funny send up of Hollywood and the actors who inhabit it. When a cabal of actors making a Vietnam War movie is dropped into the jungle for realism, they wind up next to a drug cartel and in a real war. Stiller is great as Tugg Speedman, an action star who tried to get taken seriously playing a mentally handicapped man in the horribly received Simple Jack. Even better is Robert Downey, Jr. as Kirk Lazarus, an Australian method actor who gets his skin pigmented to play an African-American. Jack Black is a scream as a heroin-addicted comedy star who has made a living farting onscreen. And, in an almost unrecognizable role, Tom Cruise gets major laughs as a foul-mouthed studio head. The film has a take-no-prisoners attitude, and it’s fun watching some of the industry’s biggest stars take shots at their bosses and peers.