In “Tropic Thunder,” one of three summer films featuring Robert Downey Jr., the actor appears on screen as a black man.Downey Jr. plays overly committed actor Kirk Lazarus, a white man cast to play a black soldier in a satire of the performing profession. The film also stars Jack Black and Ben Stiller, who co-wrote, directed and produced it.

“If it’s done right, it could be the type of role you called Peter Sellers to do 35 years ago,” Downey told Entertainment Weekly magazine. “If you don’t do it right, we’re going to hell.”

Stiller said he was “trying to push it as far as you can within reality,” with the intent of satirizing over-the-top actors, not African-Americans.

“I had no idea how people would respond to it,” Stiller told the magazine. But at a recent screening, black viewers liked the film, he said.

Downey explained that he kept the character from becoming a caricature because he “dove in with both feet.”

“If I didn’t feel it was morally sound,” he said, “or that it would be easily misinterpreted that I’m just C. Thomas Howell in (”Soul Man”), I would’ve stayed home.”

Paramount is set to release “Tropic Thunder” Aug. 15.

Donny Osmond has defied the odds of many child stars whose careers went from red-hot to has-been before age 21, and now he seems as popular as ever with a new movie and a co-hosting job on a celebrity TV show.

The singer told Reuters he also has plans for a Las Vegas show with sister Marie Osmond later this year. When he appeared on the red carpet at last week’s oscars with his wife of 30 years, Debbie, his fans went crazy.

Most are now middle-aged women who grew up swooning when a teenage Osmond sang hits like “Puppy Love,” but Osmond, who turned 50 years-old in December, seems as youthful as ever with a boyish enthusiasm for all things showbiz.

So, what’s his secret?

“Lots of plastic surgery!” he joked to Reuters. “No, it’s a mystery to me. But I think it’s good to be versatile nowadays and have a TV presence. I’m busier than ever, and I love it.”

Osmond’s new movie, “College Road Trip” debuts in theaters on Friday with Donny in a supporting role opposite comedian Martin Lawrence. Osmond plays a nerdy father of a high school girl who has befriended the Lawrence character’s daughter.

Osmond also recently began co-hosting “The Insider,” a U.S. television show that features entertainment news and interviews with film, TV and music stars.

More than four decades have passed since Donny and his four Osmond brothers began singing and dancing as a squeaky clean, All-American family act on “The Andy Williams Show.” Three decades have gone by since he and his sister had their smash hit TV variety show, “Donny and Marie.”

Rose Byrne, co-star of FX’s legal drama “Damages,” will join Nicolas Cage in the sci-fi thriller “Knowing.” The project is set to begin shooting later this month in her native Australia.

Byrne will play the daughter of a woman who buried a 1962 time capsule bearing the dates of the assassinations of historical figures, the hotel fire death of the wife of a professor (Cage) and an imminent world apocalypse. After the professor discovers its contents and alerts her, the initially skeptical Byrne begins remembering strange incidents from her childhood. Alex Proyas (”I, Robot”) will direct.

Byrne, received a Golden Globe nomination this year for her supporting turn as an ambitious young lawyer in “Damages,” which stars Glenn Close. After its first season wrapped last fall, FX ordered two additional seasons. Byrne’s feature credits include “Marie Antoinette” and “28 Days Later.”

Summit Entertainment, in theaters with the Christina Ricci drama “Penelope,” will fully finance and distribute “Knowing.”

The gloomiest week in New Line Cinema’s 40-year history ended with a clunk as the Will Ferrell basketball comedy “Semi-Pro” opened to an estimated $15.3 million, below box-office expectations for about $10 million more.

In a hollow victory, “Semi-Pro,” produced for $57 million, ranked No. 1 for the weekend, followed by Sony Pictures’ holdover thriller “Vantage Point,” which took in $13 million, and Paramount Pictures’ family fantasy “The Spiderwick Chronicles” at $8.8 million.

Executives at New Line — which learned late last week that the studio would be merged into corporate sibling Warner Bros. by parent Time Warner Inc. as a cost-saving move — declined to comment Sunday on the box-office results.

Best known for the blockbuster “The Lord of the Rings” series, New Line will continue as a production label but is expected to make fewer, and cheaper, movies. Hundreds of jobs probably will be eliminated in the transition.

Despite extensive marketing by New Line and Ferrell himself, “Semi-Pro” opened well below the star’s other recent sports comedies. “Talladega Nights: The Ballad of Ricky Bobby” started at $47 million and “Blades of Glory” opened with $33 million.

Those two were rated PG-13, while the raunchy “Semi-Pro” had a restrictive R rating that kept young moviegoers away. But even “Old School,” one of Ferrell’s few other R-rated comedies, opened better, launching to $17.5 million in 2003.

Industrywide results were down from the same weekend in 2007 for the third straight time. A year ago, total receipts were 21% higher as the comedy “Wild Hogs” led the way with almost $40 million.

Who knew pig noses could be so…pretty?

Just look at the one Christina Ricci sports in her new movie, Penelope. Ricci stars as the title character, a woman who is born with the family curse—a pig nose! The dark rom-com fairy tale hits theaters tomorrow.

Funny enough, Ricci, 28, thinks she looked better with the prosthetic schnoz than she did without it. “And then they did some visual effects afterward, which made her seem really glowy,” Ricci told me when we sat down recently to talk about the movie in a suite at the Four Seasons Hotel in Beverly Hills. “I thought, ‘Okay, that’s beautiful.’ Why couldn’t they have done that to me in the scenes when I didn’t have the pig nose?”

The flick centers on Penelope’s search for love. But things are a bit complicated: Her overprotective mom (Catherine O’Hara) has kept her holed up at the family’s estate since she was a baby because, well, she has a pig nose.

“The outside world to her is not a kind place,” O’Hara said of Ricci’s character. “So, she thinks she’s protecting Penelope from a cruel world.”

Ricci said it’s a “great metaphor” for real life.

“She’s literally trapped in a house, and we, in life, are crippled by our insecurities,” Ricci said. “We don’t go out and live our lives. It’s like you won’t go to the beach because you don’t like the way you look in a bathing suit…Accept who you are and experience life, because otherwise you never are going to.”

And experiencing life for Ricci usually means getting up at the crack of dawn because of her work schedule. “I like working,” Ricci said. “So, if I have to get up at five or six, I get excited about it…I really get into it. I love it.”

Coming up for Ricci is the May release of Speed Racer, a movie adaptation of the classic 1960s Japanese animated series. She plays Trixie to Emile Hirsch’s Speed.

“She gets to do everything that boys do,” Ricci said. “She races cars. She flies a helicopter. She fights in the fight scenes. But at the same time, her lipstick matches her shirt. She’s celebrated for being a girl because she is the only young girl in the movie, but at the same time she’s treated just like any of the male characters.”

For more on Ricci’s pig nose and to see clips from the movie, you gotta click below for my Planet Gossip Now videoblog.