It's a big day for Facebook, whose New York City employees just started to move into their brand-new Astor Place headquarters. They're so new that they aren't really even done yet. And while it's definitely a step up from the social media juggernaut's 2007 digs, the Frank Gehry-designed office space at 770 Broadway has quite a ways to go before all of the construction wraps up later this spring. The flagship Wanamaker's department store in its past life, the 1905-built structure by Flatiron Building architect Daniel Burnham is pretty green, and it's also home to AOL, Adweek, Backstage, and Billboard. The Silicon Valley-based company had some 80 employees in NYC just three years ago, according to a statement by VP Carolyn Everson, and now has more than four times that number, including about 100 engineers. They're in good company, as the site director notes, given the tech-y neighbors one block east at the
Death Star 51 Astor Place.