Oscar night, 1999. The best actor envelope has just been opened. The winner bounds onto the stage, his face streaked with tears, pausing at the podium to soak up the applause. Then he turns his back to the audience, bends over, and thanks the Academy through his butt cheeks. -- The most shocking thing about the foregoing fantasy sequence isn't the butt part, but that everything else could conceivably come true -- at least if you buy the buzz currently humming around The Truman Show, the new Peter Weir film in which Jim Carrey attempts to prove he's more than just another elastic face. His most ambitious turn to date -- he even cries on camera, something he didn't try in The Cable Guy, his last, failed stab at cinematic somberness -- it's a bracingly grown-up performance that's already winning raves and even drawing comparisons to Tom Hanks' work in Forrest Gump. ''It's not Shakespeare,'' concedes the erstwhile pet detective, ''but it's a more human character than any I've done. It's a movie about life, unrequited love, the need to accomplish something you've never been able to. It's like a Chaplin thing, with funny characters and whimsy and laughs. But it's got serious undertones and issues.''
Here's the sky-high concept: Carrey plays Truman Burbank, a slightly doofy, vaguely unhappy insurance salesman who lives in a perfect home with his perfect wife (Laura Linney, last seen as Clint Eastwood's daughter in Absolute Power) in a perfect little town called Seahaven. Naturally, it all turns out to be too perfect. Truman gradually learns that Seahaven isn't what it seems, that its inhabitants are merely actors performing in front of thousands of hidden cameras. He discovers he's the unwitting star of his own hit TV series -- The Truman Show -- that he's lived his entire life inside a colossal soundstage, his every whisper and snore secretly videotaped and broadcast around the globe.
Imagine The Real World as conceived by Rod Serling. Or the Loud family as filmed by Allen Funt. Or reality according to George Clooney. Any way you look at it, it's a pretty provocative premise in these media-mad, video-omnipotent times. The film's in-your-face symbolism -- these days all the world really is a stage, or at least a 24-hour reality-TV cable channel -- already has critics and journalists tapping out gushing exegeses on how it will ''revolutionize the art form'' (well, that's what Larry King said in his USA Today column, giving Truman higher billing than his ''I don't need Viagra'' confession). Like Gump, Truman could turn out to be as much a cultural event as a box office bonanza, a message movie for the TV-addled, privacy-starved, post-Diana '90s. As Carrey puts it, ''This film is insane with metaphors.''
Which means the implausible may now be the inevitable: The man who fell out of a rhinoceros' birth canal in Ace Ventura: When Nature Calls truly does seem poised on the brink of genuine dramatic stardom. And while nobody is talking about an Oscar just yet -- at least not without cracking a smile -- stranger things have been known to happen inside the Shrine Auditorium.