There are a lot of curious coincidences between properties of black holes and properties of the whole universe that lead some physicists to the idea that they could be connected. There's also that Penrose diagram showing another universe beyond a black hole. (Seems like a copout to me though. Penrose diagrams are drawn in 1D space, so the black hole cuts the universe in half. If you had 2D or better space couldn't you just travel around behind the black hole to the other side of it?)