I don't know if this is old, but I just discovered it. Basically, it's a web application that attempts to guess what you are thinking about by asking you a series of questions about it. It works like this - you imagine an person, place or thing, and the "A.I." asks you a series of general questions that get progressively more specific. To these questions you can give short answers like 'yes', 'no', 'sometimes' and similar. Provided you give honest and accurate answers, the A.I. is guaranteed to guess what you are thinking about after 20 questions or less! I don't know what kind of an algorithm the designers implemented here, but it works almost flawlessly - the application had no problems guessing stuff like 'slippers', 'speakers' and 'penis', sometimes taking even less than nominal 20 responses. Simply brilliant!
http://y.20q.net/anon?RUeOk6NaoDwPMDXqnMvDkO
http://y.20q.net/anon?RUeOk6NaoDwPMDXqnMvDkO