20 questions (neural network)
This is really cool. It has been around for a while so probably many of you have seen it before but I just discovered it. This is a web based version of 20 questions. You think of an object, answer 20 questions, and often the website will correctly guess what you are thinking of. Behind the scenes is a neural network that is constantly learning to distinguish your item from your answers. It actually works pretty well. It is better if you stick to tangible things like pencils and paper rather then the more esoteric like philosophy but will still get some of those.
20Q.net is an experiment in artificial intelligence. The program is very simple but its behavior is complex. Everything that it knows and all questions that it asks were entered by people playing this game. 20Q.net is a learning system; the more it is played, the smarter it gets.