Life, simple; friendship, less so: There's a little juicy speculation making the rounds as to why Paris Hilton and Nicole Richie are no longer friends, and likely will soon no longer be "Simple Life" co-stars either. (Hilton is trying to get her buddy Kimberly Stewart -- Rod Stewart's daughter -- tapped for the job, though Fox is still said to be considering other candidates.) Hilton has issued a terse statement in the matter: "It's no big secret that Nicole and I are no longer friends. I will not go into the details of what happened. All I will say is that Nicole knows what she did and that's all I am ever going to say about it." But word is that Hilton may think Richie had something to do with an incident in which a group of the girls' buddies gathered to watch a tape of Hilton on "Saturday Night Live." The tape in the VCR turned out to be not the "SNL" show but Hilton's infamous amateur sex tape instead. Ouch. (Rush and Molloy)