Toni Collette, the daughter of a truck driver and a homemaker, fell in love with acting as a teenager growing up in the suburbs of Sydney. "It was a kind of compulsion," she says. "My relationship with it has changed over the years. Initially, it was a means of just expressing myself on a basic level, and now that I've grown up, I don't depend on acting that way. I find it more in interesting as an anthropological exploration."

The craft has allowed her to explore a wide range of characters, and with films like 1995's "Muriel's Wedding," 1999's "The Sixth Sense" and 2002's "About a Boy," Collette, 33, has become one of the industry's most-respected actresses, a chameleon whose weight and accent fluctuate with the parts she plays. She's a performer who decidedly regards herself as an actress rather than a star, embracing the challenges of an exceptional variety of roles. But when she dropped out of school to pursue her dream at the tender age of 16, her parents were worried.

"They were concerned," she says. "It is a pretty dodgy industry, and the likelihood of any success is slim. I think it wasn't until I did (Anton Chekhov's play) 'Uncle Vanya' at the (Sydney) Opera House with Geoffrey Rush, three years after leaving school, that my father said, 'Maybe this will be OK.'" OK, indeed. Collette's turn as Cameron Diaz's dowdy sister in Fox's "In Her Shoes," director Curtis Hanson's adaptation of Jennifer Weiner's popular chick-lit novel, has some suggesting that she's primed for awards-season attention despite the film's lackluster boxoffice performance.

Grosses aside, the film is one of the more high-profile women's vehicles of the past few years, with Diaz and Collette as warring siblings who find common ground thanks to their grandmother (a very understated Shirley MacLaine). Collette says she enjoyed an instant rapport with her glamorous co-star Diaz. "I was absolutely petrified," she says of taking on the project, for which she had to gain nearly 30 pounds. "At the same time, there was this deep-seated knowledge that it was meant to be. Cameron and I just clicked. There was no forced effort or manipulation to create the bond you see onscreen."

She adds: "I see Cameron for who she is. She is incredibly grounded and easygoing. She calls herself a cynic, but I think she is the most optimistic person. She is the most un-Hollywood of all Hollywood stars." Except, of course, for Collette herself, who, unlike so many foreign-born talents, continues to reside in her native Australia. "I love my home here," she says. "I lived in London for a while -- I bought a flat in Brixton, and it was just horrible. I don't know how people put up with the weather."