Contact
Hello, this is the Doctor speaking. Except that it's not me speaking because you're talking to the TARDIS' answering machine. Leave a message and I'll try get back to you.
Unless, of course, you haven't met me yet. Or I haven't met you yet. In that case, it would probably be best for you to hang up. Wouldn't do the universe any good to muck up the timeline because of one wrong number.
Right, if you are sure that I've met you and you've met me and we are at the same point in each others timeline, please leave a message and I'll get back to you.