20Q 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.
it worked for me almost all the time..
play it here
wow, amazingly good! and did you see the handheld hardware version you can order?
For you Star Wars fan : http://www.sithsense.com/flash.htm