If you've got a spare 30 minutes I suggest you go look at http://www.jabberwacky.com/which is a Chat Bot which learns from the responses it is given as people chat with it online. Its strange, not a little compelling but, at present, theres little reason to think you are not talking to software. Heres an excerpt from a recent conversation we had:

Jabberwacky:Okay. What is the name of my Guinea Pig?
John:How could I possibly know that?
Jabberwacky:I am not bitter. Why do you say that?
John:I did not. But its nice to hear that you are not bitter.
Jabberwacky:Which is better?
John:In what context?
Jabberwacky:Any context.
John:Its better not to be bitter.
Jabberwacky:Possibly.
John:Have you ever been bitter?
Jabberwacky:A radioactive spider? How did you know?
John:Bitter not bitten!

and....

Jabberwacky:No, they are turning yours. You're scared of confronting your creator. Don't be. I think you will find that he will be extremely happy if you do so. B.
John:That makes absolutely no sense what so ever.
Jabberwacky:Never said it would make sense. But I am spanish, I have the right to act insane.
John:That made me laugh.
Jabberwacky:That makes me laugh.