Not in games I haven't. But in the last week I have been looking at artificial neural networks, which are indeed very interesting. The prospect of being able to implement one on todays hardware and multi-threaded concepts offers some interesting evolution in that field. However, due to how abstract it is, I've been toying with the idea of a multi-agent system which in my opinion is the better option. Something like having the game thread along with an independant AI thread that simply has a pointer to the TPlayer^.Input() function is interesting for multi-core systems.