Sometimes I'm convinced that my computer can read my mind. A good example is http://www.20q.com, an online 20 questions game that uses the inputs over all these years in a learning AI program.
The program has been learning since 1988. The questions it asks seem to lead it no-where, then suddenly it has the correct solution. You can read more about its origins at http://www.monitor.ca/monitor/issues/vol6iss9/feature5.html .
The game even taunts you. Once it got to question 20 then said, "Looks like you win", then "Just joking!" and gave the correct answer.
Usually it tells you it has the right answer around question 15, then goes on asking a few more questions so it can learn more about the item you have in mind before revealing your item. It's always learning.
I bought the handheld version, and I'm blown away by what it knows in such a small package. It got "power cord," "aardvark," and "sports car" without any trouble. It's available on Amazon for less than $14USD. My kids love it.
... but I'm a little creeped out by it. It knows what I'm thinking...