There is also OpenCV http://opencv.willowgarage.com/wiki http://opencv.willowgarage.com/wiki, which I believe has several wrapper libraries that add higher leve

There is also OpenCV http://opencv.willowgarage.com/wiki http://opencv.willowgarage.com/wiki, which I believe has several wrapper libraries that add higher level functionality. PHP, for one, has a face detection library: http://www.xarg.org/project/php-facedetect http://www.xarg.org/project/php-facedetect