SAN FRANCISCO, CA - SEPTEMBER 22: Comedian Andy Sandberg pretends to be Facebook CEO Mark Zuckerberg during the Facebook f8 conference on September 22, 2011 in San Francisco, California. Facebook CEO Mark Zuckerberg kicked off the conference introducing a Timeline feature to the popular social network. (Photo by Justin Sullivan/Getty Images)
Facebook's f8 conference
Facebook unveils a range of new features at its fourth annual f8 Developer Conference in San Francisco.