Zellweger Goes Retro in 'Down With Love'

May 15 -- In Bridget Jones's Diary, she put on weight. In Chicago, she put on dance shoes. Now, Renée Zellweger puts a feminist spin on 1960s-era romantic comedies.

Zellweger, 34, wasn't even alive when Doris Day and Rock Hudson lit up the screen in such classics as Pillow Talk, Send Me No Flowers and Lover Come Back. But she thinks her generation has a special spot for those campy, wholesome romps — although she's not exactly your mother's Doris Day.

In Down With Love, opening Friday, Zellweger has Day's feminine playfulness, but her character, Barbara Novak, is a trailblazer who tells women to swear off love, have casual sex, and pursue a career.

"There's an innocent, playful feeling among the characters. The flirtation and banter is classic movie boy-girl behavior from that era," says the two-time Oscar nominee.

"There's an aspect of this movie that tries to capture that feeling you get when you're a kid chasing a boy around the playground. And then you catch him and don't know what to do. It's just plain fun."

Raiding Mom’s Wardrobe

Zellweger was greeted this morning on ABCNEWS' Good Morning America by an audience largely clad in the 1960s outfits that play such a prominent role in the film. Her co-star Ewan McGregor also turned up to perform the movie's theme, "Here's to Love," which they sing on screen.

"I look at these things and I see my mother's closet way back when," Zellweger says, admitting that she's raided mom's wardrobe for some vintage outfits.

"I have this great coat that she was so proud of — a swing coat with a mink collar … She loved this era."

Both Zellweger and McGregor are coming off musicals, and while Down With Love only contains one song — slapped on as an afterthought at the end of the movie — she says her work in Chicago paid dividends in her new role.

"It was never intended," she says. "Ewan McGregor was wailing around the set saying, 'Should we do a song? Don't you think we should do a song?' The film has such energy to it that it just seemed natural. Finally they gave and did it."