Some actresses take a risk by signing on to an unglamorous role. Others do it with a high-profile nude scene. But Annette Bening has taken perhaps the biggest risk of all with Being Julia: She plays her age. As Julia Lambert, a British stage actress who's supremely paranoid over her just-beginning-to-wane star status, Bening, 46, infuses the already juicy role with equal parts devilish humor and heartbreaking vulnerability. ''A number of women that I've talked to who are my age say there's almost this 'coming out,''' she says. ''It's like a second adolescence, except that you're wiser. There's a kind of rebirth and rejuvenation.'' And thank God for that. After four years of virtual absence from the screen (appearing only as Kevin Costner's love interest in 2003's Open Range), Bening's finally found a role that's as worthy of her talents as her Oscar-nominated turn in American Beauty. She didn't nab the trophy for her portrayal of Beauty's tightly wound real estate agent, Carolyn Burnham, but she'll no doubt find herself in the running for Best Actress for Julia, since she's already won that honor from the National Board of Review and earned a Golden Globe nod. Not that anyone needs to tell Bening that this is the role of a lifetime: ''I remember reading it and just being knocked out, thinking, Are you kidding? Yeah!'' Precisely our response.