chess playing robot

[chess06]

hello guys.
i am making a robot which can play chess. I am planning to use arduiono but i am not sure how i can make robot understand what was my move. I dont want to use image processing its to heavy for me. Any ideas ? may be sensors ?
thanks

 

[Supercap2F]

How about using Reed switches under the board to detect magnets on the bottom of the pieces - like this guy did.
Dan