On Oscar night, one gorgeous gown simply isn't enough some of Tinseltown's biggest stars. The actresses below made the most of the red carpet marathon by changing from award show frocks to after-party dresses. Naturally they all reconvened at the biggest fete of the evening - Vanity Fair's annual bash at Sunset Towers.

The reigning queens of the red carpet, Jennifer Lopez and Cameron Diaz know how to go from Gaga-esque gowns to downtown divas in no time.

J.Lo's long black cutout number by Gucci is a stark contrast to the princess-like Armani Privé frock that she wore to the Oscars ceremony. In addition, she ditched her perfectly mussed bun in favor of a slicked back ponytail.

Diaz, meanwhile, ditched her embroidered Oscar de la Renta ballgown for a a one-shouldered Victoria Beckham dress from the Fall 2010 Collection. It was the second time in the evening that the actress touched on the omnipresent metallic trend.

"Avatar" actress Zoe Saldana earned top marks for her daring Givenchy Haute Couture confection made of ruched silk organza with degradé detail. Later in the evening, she chose to stick with Riccardo Tisci's ombré designs with a look from the Fall 2009 couture collection.

Diane Kruger also went for a risqué look in Chanel Haute Couture for the Oscars. By the time the party started, she had slipped into a translucent red sheath by Francisco Costa for Calvin Klein Collection.

Like Saldana, Best Supporting Actress nominee Anna Kendrick stuck with the same designer for her Oscar and post-show party looks. Her long pale pink Elie Saab gown was swapped for a flirty white cocktail dress for the end of the night antics.

Her fellow ingenue, Amanda Seyfried, also opted out of her voluminous Armani Privé gown for a short Valentino whip of a dress. (The stacked Lorraine Schwartz cuffs remained firmly in place, though.)

Check out all the Oscar party photos right here.