A few:
Jackie Onassis frequently had dinner at the house of a friend of mine.
George Segal's daughter, Alix, was my intern once upon a time (I'm gambling that fathers count as friends). I liked her a lot. I only figured out who her father was because of the occasional, casual reference to details about her past (her buddyship with Jodie Foster, for example).
Mordecai Richler's daughter, Martha, was an intern at the same joint.
My father was acquainted with William Mandel (famous, among other things, for saying to Senator McCarthy during a Senate committee hearing, "This is a book-burning! You lack only the tinder to set fire to the books as Hitler did twenty years ago, and I am going to get that across to the American people!"), who gave a rousing speech from our back porch in Columbus, Ohio, when I was four. As he spoke I sat at his feet playing with a three-legged dog (survivor of a lawn-mowing accident). (My father lost a job because of the whole business, and my mother still has the hate mail they received afterward. I really do need to ask her to dig that out for me sometime.)
