Paris Hilton and Nicole Richie are officially on the outs. "It's no big secret that Nicole and I are no longer friends," Hilton said in a statement. "Nicole knows what she did and that's all I'm ever going to say about it." Last week, Hilton revealed that Rod Stewart's daughter, Kimberly, would be replacing Richie in the upcoming fourth season of The Simple Life, although Fox insists no decision has been made — mostly because they've been too busy figuring out new and creative ways to further enrage Tru Calling fans.