(Start with:) Hello, this is Adrian; I'm just returning your
call.
(Later change it to:)
Hello, this is Adrian; I'm just returning your call. If you
haven't made a call yet, please do so now, because if I try to
answer a call you haven't even made yet, it could create a
temporal paradox, which could seriously disrupt the space-time
continuum, and possibly even cause the entire universe to
implode. And you wouldn't want that to happen, now, would you?
-- Answering machine madness - playing with the caller