http://cleverbot.com/

This little thing is so much fun hahahaha
You can even talk smack to it and it can dish what it takes sometimes hahaha xD
You must try it out and if you're anything like me you'll fall in love with it bahahaha xD
Try it try it try it
You know you want too o.O

Note: shortly after originally posting this I pissed it off and it doesn't want to talk anymore bahahahahaha xD

You do realize that clever bot is actually just another person, not a machine. The website links up 2 visitors and let's them talk for about 30 seconds, then it links u with another person without u knowing. That's why "cleverbot" randomly chances conversation.   

Don't belive me? Try going again but pretend that you are cleverbot and see how the roles reverse, then the other person will start asking you stuff like "what's it like being a robot"

After a while I got a feeling that's what was happening.  Still kind of interesting.

It was fun for a little bit, but it's not a very good conversationalist. It kept changing subjects like crazy!

I played around with Clev for a little bit. Then shorted the poor fella out. Hehe

YES!
You have achieved what I was trying to do bahahahaha
Get the thing to not want to talk anymore and not let me talk anymore xD