Lake Bell

Kate Bosworth showed skin in a backless ensemble for the premiere of her latest film, Black Rock, in Hollywood last night. She was accompanied by her costars Lake Bell and Katie Aselton for the festivities. Ed Helms also made an appearance at the premiere for the film, which debuted at the Sundance Film Festival back in January and will be released in the US next Friday.

It has been a big week for Kate, who jetted back to the West Coast for her premiere following a Met Gala appearance on Monday in NYC. Kate donned a pink Balmain dress and was joined by her fiancé, Michael Polish, for fashionable festivities in the Big Apple earlier this week. Don't forget to vote for Kate in our POPSUGAR 100 bracket for a chance to win a Victoria Beckham handbag!

Josh Hartnett got in on the pre-Oscars parties when he dropped by the Vanity Fair and Fiat party benefiting the United Nations International Labour Organization in LA last night. The star-studded event, which was hosted by Ron Howard and composer Hans Zimmer, also included Lake Bell, Alyssa Milano, and Adrien Brody as guests. Josh had a busy evening, as he also visited the Hollywood Domino and Bovet 1822 event in West Hollywood. Alyssa — who wore Gucci to last night's event — will likely have a lot more Academy Awards-related events to attend this weekend, since her husband, David Bugliari, reps Bradley Cooper, who is nominated for best actor. Bradley has a lot of events on his plate this week, including Wednesday night's Vanity Fair dinner for Silver Linings Playbook, which he attended alongside costar Jennifer Lawrence and director David O. Russell. Don't forget to join us for our LIVE Oscars viewing party and red carpet coverage on Sunday, Feb. 24 at 5:30 p.m. EST/2:30 p.m. PST.

Jake Gyllenhaal was honored in NYC last night at the New Eyes For the Needy 80th Anniversary dinner. He was joined at the intimate event by friend Lake Bell and her fiancé, tattoo artist Scott Campbell, and costars from his latest Broadway production, If There Is I Haven't Found It Yet. Jake's been a longtime supporter of the philanthropic organization that provides glasses for children and adults who can't afford to purchase prescription eyeglasses on their own.

Jake's baby blues have apparently grabbed the attention of a new lady in his life. Jake was spotted holding hands with an unidentified brunette recently in the Big Apple. He might be off the market again, but an old romance has rekindled interest in his personal life. Many speculate that Taylor Swift's latest single, "All Too Well," is about her relationship with Jake.

Jennifer Aniston wore Tom Ford to last night's big LA premiere of Wanderlust. She shared hugs on the red carpet with costars Paul Rudd and Malin Akerman, as well as producer Judd Apatow and his wife Leslie Mann. However, Jennifer seemed to keep her distance from boyfriend Justin Theroux. Jen and Justin weren't photographed together at all throughout the evening, but both were still wearing their personalized "Jennifer" and "Justin" name rings. They even managed to stay a few feet apart during the afterparty at Napa Valley Grille. Justin caught up with Paul and his wife Missy Yager at the bash, while Jennifer hung out with Universal Pictures president Ron Meyer. We were on the scene last night at Hollywood's Mann Village Theatre, so stayed tuned later for our report from the screening.

Lake Bell and Kate Bosworth made a picture-perfect pair at the premiere of Black Rock during the Sundance Film Festival on Saturday. The girls star together in the picture from director Katie Aselton, and the trio also got together for a Q&A about the project. Kate said of seeing Black Rock for the first time, "I'm excited to be in the audience for the film like this, you taking what Katie does so well her tone and applying it to a thriller. I think it will be a really really neat experience as an audience member."

Kate took advantage of her newly launched Twitter account to share updates from the screening. She tweeted back and forth with her stylist Cher Coulter about her red Antonio Berardi dress. Kate's boyfriend Michael Polish also got his own new account, and both he and Kate sweetly directed their first tweets at each other. They've since shared pictures and updates from "Snowdance."

First, mark you calendars for March 13, this Sunday, when Target GO International releases the designer collective collection, a greatest hits of some of the past 10 years of designer collaborations. Remember how you never got that Rodarte dress? Well, here's your chance. The party, held at the Ace Hotel in NYC, was rockin' with Chloe Sevigny, Michelle Trachtenberg, Olivia Munn, Liv Tyler, and Lake Bell coming to check out dresses and listen to Santigold's live performance. Click for the full slideshow — what do you think of Chloe's outfit in particular?

Natalie Portman picked a peephole Vena Cava dress last night for the LA premiere of No Strings Attached. She hit the red carpet without fiancé Benjamin Millepied, but her costar Ashton Kutcher was happy to pose next to his Carven-clad wife, Demi Moore. Her daughter Rumer Willis smiled solo just ahead of today's release of her new Badgley Mischka ads. We caught up with Ashton as he headed into the screening, and he said unfortunately Natalie's on her own when it comes to parenting tips since he really only knows about kids older than 8! Their castmate Greta Gerwig said, though, she was thrilled about Natalie's surprise pregnancy and revealed that the mom-to-be is an amazing vegan cook. Greta kept company with a green-clad Lake Bell and Mindy Kaling, who summed up the evening by tweeting, "It's not gonna get much cuter than tiny Natalie Portman, pregnant."