Write a conversational IRC bot, lol.
I Figure, load two processes, a communications layer and an automation layer; in this case the communications layer would be a simple relay between an IRC channel and the automatas standard I/O streams; messages on the channel would get written to the automatas standard input, and messages to send to the channel would be read from the automatas standard output.
I would want the thing to have some concept of learning, maybe build a dictionary of language; perhaps start off with a limited knowledge of words; storing words it doesn't know into a database for later analysis. And then once a number of words have been manually entered into it with attached meta data, program it to perform the analysis itself; trying to figure out what kind of words it sees but doesn't know about yet, and then write out plugin code with the bots "best guess", and if it gets it wrong, I could manually change it, and it would have to study the differences between my correction and it's choice, and modify it's guessing based on experience. (Implementing that would be fun in it's own right, lol.).
That would logically be easy enough to design and study, the question is how to make it educating enough that you can actually have people chatter with it.
Haha, I always laugh when people mistake bots for humans on IRC xD