When 2010 became 2011, the real action (sorry, Snooki) was in Vegas, where Jay-Z and Coldplay’s Chris Martin teamed up for a special concert to open the new Marquee at the Cosmopolitan—a concert that drew wives Beyoncé and Gwyneth Paltrow as well as Kanye, Rihanna, Blake Lively, J. Lo, A-Rod, and more. Meanwhile, in Miami, Chloë Sevigny hosted a bash at the Mondrian with Miike Snow’s Andrew Wyatt that brought out Leigh Lezark and Leona Lewis, and Nur Khan partied at Kenmare and Don Hill’s in New York City, where his photographer pal Sante D’Orazio set up Sante’s Inferno. Missed the fun? Click through our slideshow for all the pics.