Michelle Trachtenberg

Heidi Klum played Halloween hostess yet again last night with her bash at the Ph-D Rooftop Lounge at NYC's Dream Downtown Hotel. She was just in Las Vegas for the Nevada version of her annual holiday soirée and, for that occasion, was covered in body paint and minimal fabric as "the visible woman." However, yesterday's event required more covering up — and fur! Heidi and her husband Seal were dressed as monkeys, and she tweeted that they were "mad happy!" The evening of socializing came after a nonstop day for notorious Halloween fan Heidi, who swung by Live With Regis and Kelly as well as Late Night With Jimmy Fallon to record special appearances. Many other celebs turned out for Heidi's event, including models Chrissy Teigen and Doutzen Kroes as well as a Toddlers and Tiaras-clad Fergie.

The front row at last night's Marchesa show during NY Fashion Week was packed with stylish stars. Bar Refaeli, in a sexy black number and hot pink lips, sat next to Petra Nemcova while Mandy Moore posed for pictures with Emma Roberts. Kelly Osbourne made a solo entrance, Michelle Trachtenberg stood out in a dark blue dress, and Naomi Campbell mingled backstage with fellow models. Rachel Zoe brought husband Rodger Berman along for the fun after she presented her own collection earlier in the week. The designer had her son Skyler close by for the event and Rachel talked about how motherhood has mellowed her out and also shared her favorite pieces from the line. It's been an exciting week so far and there are plenty of NY Fashion Week celebrity pictures to see — check them out now!

Last night, Mulberry celebrated its 40th birthday, drawing a crowd of fashion week front-rowers and stylish celebs to NYC's Skylight Studios West to fête the anniversary. While the crowd sipped Prosecco and noshed on miniature rice-crispy treats, Kasabian rocked the rooftop lounge, drawing Alexa Chung and Anna Dello Russo to the dance floor. There, we spotted Gossip Girl's Georgina, aka the lovely Michelle Trachtenberg, and found out exactly what the actress has on her Fall wish list. Check out Michelle's fashion must haves, and then click through for a glimpse of all the celebs at last night's bash.

• On the perfect pair of pants: I think I'm of the age where I need to start investing in smart pants. I'm not talking anything pleats, I'm just talking about menswear-inspired, as opposed to always reaching for my black skinny jeans.
• On the search for a great coat: I'm looking for a great gray [coat] — kind of like a mix between a wool and a silk trench coat if that makes any sense.
• On the perfect Fall shoe: A really great statement shoe, a colorful heel.

Source: Michelle Trachtenberg Talks Fall Fashion at Mulberry's 40th Anniversary Bash

Diane Kruger rocked a shorts suit last night for a party thrown by InStyle. The bash, held inside West Hollywood's London Hotel, brought out other starlets like Jaime King, Lea Michele, and Jordana Brewster. Diane's ensemble was from her pal Jason Wu's resort collection — see what the other celebs wore to InStyle's Summer soirée. Diane had a night with her lady friends after a few fun outings with her main man, Joshua Jackson. They had a sweet day date last week checking out Captain America, as both Josh and Diane gear up for the return of his show Fringe on Sept. 23.

Jessica Alba covered her baby bump in an animal-print maxi dress by Dolce & Gabbana for a party in LA last night. The bash was held to celebrate a partnership between ThisNext.com and Lucky, which features Jessica on the September cover. Jess was surrounded by pals for the event, which also benefited the Baby 2 Baby charity since Jessica is a board member of the organization. Expecting mom Ali Landry stepped out to support the cause, as did Michelle Trachtenberg, Jordana Brewster, and Jeffrey Allen Marks and Ross Cassidy from Million Dollar Decorators. Lauren Conrad was on hand in another fitted white dress after hitting the red carpet in a neutral mini at a Rebecca Minkoff bash on Tuesday. The always fashionable Lauren Conrad even shared her beach basics on FabSugar.

From fashion editors giving us sneak peeks at fashion shoots and designer collections to the stars sharing parts of their daily life, it was a fun week in Twitterland. Click through our slideshow to see some fun shots from our favorite tweeters.

Blake Lively was back out on the Upper West Side to film Gossip Girl yesterday. The actress wore a warm padded coat over her fancy gown, as did Michelle Trachtenberg and Jessica Szohr. Michelle tweeted pictures from the set, and said she was "thrilled to be causing mischief" as the naughty Georgina Sparks again. Blake chatted with Penn Badgley the day before, as they shot scenes alongside Jessica, Chace Crawford, Connor Paolo, and Ed Westwick. Ed also giggled with Leighton Meester as they started filming the finale at the beginning of the week. Blake was in Paris at the weekend for a Chanel dinner to celebrate her Mademoiselle handbag ad, and adorable backstage photos of Blake have just been released.

Kellan Lutz looked sharp last night at the Hollywood Domino gala in LA, where he mingled with celebs including Paris Hilton, Dave Annable, and Danneel Harris. He wore a black suit, shirt and grey tie for the occasion, and left his adorable dogs at home. Kellan's Breaking Dawn costar Ashley Greene spent some time with boyfriend Joe Jonas yesterday and has instructed Twilight fans to watch the Oscars, while Robert Pattinson's working hard on the film. Kellan's among the many young actors slated to be in with a chance to star in the Bourne spinoff directed by Tony Gilroy. Click through for more photos including Michelle Trachtenberg, Odette Yustman and more!

Harvey Weinstein and Dior held an Oscar dinner at Chateau Marmont last night. Nice host of the awards Anne Hathaway posed with Lily Collins and The King's Speech director Tom Hooper, while Ginnifer Goodwin cuddled up to Emmy Rossum. There were lots of smiles as Busy Philipps hung out with Rosario Dawson, and Gerard Butler joked with Adrien Brody. Halle Berry had Olivier Martinez for company, after flying solo at the Costume Designers Guild Awards the night before. Michelle Trachtenberg, Chelsea Handler, and Sharon Stone were amongst the other guests at the fun do.

Leighton Meester and Minka Kelly just attended the premiere of The Roommate, and last night they were out celebrating Leighton's Nylon magazine cover. They were joined by Gossip Girl's Jessica Szohr and Michelle Trachtenberg, and Kanye West and Jared Leto also attended the bash. The show returns tonight on ITV2, and the cold cast have been filming in snowy NYC lately. Will you be watching?