Tears, jeers and cross-dressing: Oscar night drama in store
From winners sobbing uncontrollably to shocking political outbursts, bizarre snubs and streakers, the Oscars have seen it all, and Sunday's Academy Awards will likely provide fresh drama of its own.
Organizers of Hollywood's biggest night are white-knuckled as they brace for more tales of the unexpected that could anger viewers or throw the finely-calibrated global telecast off schedule.
But the raw emotion and the unscripted moments of what remains a tightly choreographed extravaganza are also what makes Oscars night memorable.
With a global television audience in the billions, the temptation to use the event as a platform for political statements has proved irresistible throughout the years.
Taking a swipe at critics who say Hollywood is out of touch, Oscar-winner George Clooney in 2006 noted that moviemakers had crusaded for civil rights and against AIDS long before the issues became popular.
"I'm proud to be out of touch," Clooney said.
As statements go, it was on the mild side.
Three years earlier, boos rang out around the auditorium when maverick filmmaker Michael Moore launched a vitriolic attack on US President George W. Bush for waging war in Iraq.
But Moore was only following the tradition of turning the winners podium into a pulpit.
Arguably the most famous example came in 1973, when a woman calling herself Sacheen Littlefeather stood before the stunned audience to collect Marlon Brando's best actor Oscar for "The Godfather."
Littlefeather promptly refused to collect the award on Brando's behalf to protest the movie industry's treatment of Native Americans.
Four years later, Vanessa Redgrave drew gasps and boos from the Oscars faithful when she thanked the Academy for honoring her in "Julia" despite "the threats of a small bunch of Zionist hoodlums."
In the same awards ceremony, Oscars presenter Paddy Chayefsky chastised her to much applause: "I am sick and tired of people exploiting the Academy Awards for the propagation of their own personal propaganda.
"I would like to suggest to Miss Redgrave that her winning an Academy Award is not a pivotal moment in history, does not require a proclamation, and a simple 'Thank you' would have sufficed."
Sometimes, the choice of awards recipients can stoke controversy.
The decision to grant director Elia Kazan a lifetime achievement award in 1999 divided the glitterati, with dozens of stars refusing to rise or applaud, in protest at the filmmaker's decision to co-operate with the authorities during the 1950s communist witch-hunts.
Politics aside, Oscars night has been littered with memorable one-offs.
In 1974, a naked man invaded the stage as actor David Niven was hosting the show, prompting him to quip: "The only laugh that man will ever get in his life is by stripping ... and showing his shortcomings."
More recently, in 2003, actor Adrien Brody stunned viewers and superstar Halle Berry by kissing her passionately on the lips as she presented his best actor statuette, creating an Oscars signature moment.
Italian Roberto Benigni made a stir in 1999 when he euphorically leapt onto a chair and jumped from one seat to the next when he won the best foreign film Oscar for "Life Is Beautiful."
And in 2000, the irreverent creators of the animated show "South Park," Trey Parker and Matt Stone, turned up on the red carpet in drag to poke fun at the cross-dressing theme of the nominated film "Boys Don't Cry."
Several years later, the duo revealed they had taken the hallucinogenic drug LSD before their gender-bending red-carpet performance.
"We took acid and tripped," Stone said in 2006. "It seemed like the right day -- drop acid and get on the red carpet in a dress. I haven't taken acid since then."