Paris Hilton and Nicole Richie

Paris Hilton and Nicole Richie grew up together and created their own reality show, The Simple Life, which was based around their friendship. But the show was abruptedly axed in 2005 after its two stars fell out when, rumour has it, Nicole poked fun at the heiress' sex tape. "All I will say is that Nicole knows what she did and that's all I am ever going to say about it," Paris squeaked.