Black-tie benefits and film screenings kept this crew of celebrities very busy, not to mention, impeccably dressed, throughout the weekend. Last night, styled celebs gathered for a good cause, stepping out in Hollywood to support the Trevor Project, which provides support to lesbian, gay, and transgender youth. Among the attendees, we spotted the lovely Zoe Saldana in a printed mini, while Amber Heard took an elegant approach in a creamy white gown. In DC, Sarah Jessica Parker made a glamorous arrival at the 34th Kennedy Center Honors event, joining a newly engaged and glowing Anne Hathaway for last night's festivities. But that's not even the half of it — fashion darling Olivia Palermo hit the red carpet with Madonna for an NYC film screening, and Katy Perry donned white-hot Versace for the annual Change Begins Within benefit in LA. Click on for all of this weekend's red-carpet action.