There is barely a person in the western world who hasn't heard of Facebook - the largest online social-networking service on the planet. Whether they are sharing photos with their friends, posting a status about how they are feeling or tagging themselves at a venue to show exactly what they are up to, the world's population have become obsessed with social media - and most particularly Facebook. Launched by Mark Zuckerberg in February 2004, in little over a decade Facebook has gone on to dominate the online social-networking market - and there are no signs of its rapid expansion slowing down anytime soon. Facebook's CEO Zuckerberg - along with his Harvard University roommates Eduardo Saverin, Andrew McCollum, Dustin Moskovitz and Chris Hughes - established the website for their fellow Harvard students, but eventually expanded it to the general Boston area and then to the world. But what do we we actually know about Facebook? Which world-famous Hollywood actor, for example, was the inspiration behind the original "face" in the website's first logo? What alternative name was Facebook's "like button" almost given? And, with Facebook offering its users more than 60 languages to choose from, what is the most-unusual ones people can set their account to? Well, here are 18 mind-blowing facts about the biggest social-networking website in the world, Facebook.