Keira Knightley takes the plunge

One of Oscar nominee Keira Knightley's fave British designers - Jenny Packham - will have a special fashion show in Los Angeles in October, just in time for  2007 award season shopping. The show will be sponsored by BAFTA/LA.

Packham, who usually parades her wears on London and Paris runways, has been dubbed "the first lady of partywear" by British Vogue, who certainly should know.

No doubt a few of her fervent fans like Nicole Kidman, Mandy Moore, Kate Moss, Mena Suvari, Brittany Murphy, Heidi Klum and Scarlett Johansson, who just wrapped the new Woody Allen film "Scoop" in London, will show up for Packham's show.

Knightley and Packham just worked together on a photo to aid Fresh2o, a campaign to promote WaterAid, which provides African and Asian communities safe domestic water supplies. In this eerie underwater shot by aquatic photographer Candice, Knightly (gulp) manages to hold her breath beautifully in a frothy cream Packham gown.

Just so you know, Knightley, who walked the red carpet wearing white Chanel at Saturday's premiere of "Pirates of the Caribbean: Dead Man's Chest" at Disneyland, flew back to jolly old England the very next day to keep filming Ian McEwan's "Atonement," which has, to say the least, an impressive female cast.

On the "Atonement" roster: Emily Watson, Brenda Blethyn, Vanessa Redgrave, Kristin Scott Thomas and... Betty White.

Yes, that Betty White, best known for playing sexually voracious Sue Ann Nivens on the '70s TV series "The Mary Tyler Moore Show" and for her loveable ditzy Rose on the early '90s  hit series, "Golden Girls." Who knew?

Photo Credits: Keira is a bathing beauty for charity in a Jenny Packham gown.
Courtesy of WaterAid.