Facebook, the site which seems to never stop growing celebrates its 6th birthday today. The social networking site now boasts 400 million users, according to founder Mark Zuckerberg. Events planned for the occasion include a party at Facebook headquarters and "a handful of new things" for the site, such as a top menu and a "Windows Explorer-style" left menu. A complete list of the recent updates can be viewed here. Lets face it, Facebook is a part of many of our lives and we just wouldn't be the same without it. So here's to many more years of Facebook!