Have you seen 20Q.net? It's a really great artificial intelligence program that plays the 20 Questions game with you. According to the site: "Think of an object and the A.I. will try to figure-out what you are thinking by asking simple questions. The object you think of should be something that most people would know about, but, never a specific person, place or thing." It's a blast, really. I've beaten it a few times but only stumped it completely once.