Oscar Fashion: Roberts Ruled, J-Lo Unspooled

Old Hollywood seized New Hollywood by the spaghetti straps at the 73rd Academy Awards, where modern celebs adopted the demure looks of flappers, red-lipped '40s starlets, and Southern belles.

Best Actress winner Julia Roberts, who typically attends awards shows in somber but classic gowns, chose a striking vintage Valentino from the '80s. The black column dress was enhanced by Y-shaped white piping and was apparently so tight that Roberts sought the advice of her Best Actress predecessor, Hillary Swank.

"Every time [Swank] passed me, she would say, 'Breathe. Just breathe,'" Roberts revealed to reporters backstage. "Not so easy in this dress, but I'm doing the best I can."

Another Best Actress candidate wowed fashionistas with her very own vintage Valentino: Laura Linney was vibrant in her tangerine/red gown, which had tapered shoulder straps that were anchored by tiny bows. You Can Count on Me's leading lady also chose minimal makeup and a glamorous, crisscrossed upsweep for her hair, a style shared by Catherine Zeta-Jones and Roberts.

Faux Pas or 'Ooh-La-La'? The only two actresses who seemed oblivious to the nostalgic look of this year's Oscars may have adopted their daring style from years of making music videos: Pop diva Jennifer Lopez and Icelandic chanteuse Björk both raised eyebrows — Lopez arrived in a transparent, smoky gray Chanel gown she (mistakenly) chose just before the ceremony, and Björk tiptoed into the Shrine Auditorium clad in a childlike gown made to look like a swan.

Lopez's nipples were the talk of the ceremony, and cameramen rushed to pan away from her bust as she walked onstage to present the Best Original Song Oscar. Meanwhile, Björk — whose Dancer in the Dark tune was nominated in that category — drew both scorn and praise for her fluffy feathered friend, which concealed a fake egg that she had earlier "laid" on the red carpet. Mr. Showbiz staffers, though, largely agreed that Björk's look deserved kudos for being so, well, Björk-like.

Best Supporting Actress nominee Kate Hudson wore one of the night's true missteps, a bland, fringed cowgirl jacket with a train from über-designer Stella McCartney. Hudson's usually shiny blond locks were fried into a nasty permed mess, sort of like Dolly Parton's in 9 to 5, and piled on top of her head. She looked 49 and frazzled instead of 21 and happy.

Another of the night's fashion losers was Best Supporting Actor nominee Joaquin Phoenix, who materialized in a rumpled white shirt (sans tux jacket) and the worst bed-head this side of kindergarten. It turns out that Phoenix had just awakened prior to arriving, so he simply pulled on his tux and ran out the door. If that's how little his Oscar nod meant to him, we're glad he lost to Benicio Del Toro.

True Contenders Know Couture The upset of the night may have been Marcia Gay Harden's Best Supporting Actress statuette, but her channeling of Katharine Hepburn circa 1947 was just as delightfully shocking. Harden, wrapped in a cranberry Randolph Duke that hugged her curves, arrived with two decadent accessories: a sparkly, red Wizard of Oz-type clutch and a rather large bodyguard, courtesy of jeweler Harry Winston, who'd lent her an enormous diamond collar.

The Contender's Joan Allen was outfitted by Michael Kors, who made the statuesque Best Actress nominee a custom gown adorned with real coral beads. French actress Juliette Binoche (Chocolat) caught a few snide remarks for her flapper-style black dress, feather headpiece, and multiple pearl strands, but we thought she looked gorgeous. Likewise, Ashley Judd's slicked back 'do and diamond headbands were pure Roaring '20s, and it worked well for the perky actress.

Crouching Tiger, Hidden Dragon star Michelle Yeoh shone in a black-and-gold sequined dress from Hong Kong designer Bonnie Chang, but she shimmied out of the 35-pound ensemble as soon as the ceremony ended. — Kristy Martin, with reporting by Larry Terenzi

Click here for a complete list of the winners.