In one of my previous posts I promise to tell something about openCV now it is closely related to machine learning http://www.cognotics.com/opencv/docs/1.0/index.html I would refer to the site for further details.It can be used for various techniques and implement in face recognition.So who want to do projects on that interesting subject pls take a look. U can use easily it in your robot and can make it a interacting bot, all the software you have to download you will get here,feel free to contact me at sarkarcse@yahoo.com anytime......
regards...