Just as the title says, how does they way the Playstation 2's EyeToy calculates where things are compare to how the 360's Kinect does it?
The PS2 EyeToy is essentially a QVGA (320x240) webcam, which is paired with image and gesture recognition software to create a device capable of detecting objects and simple movement.
Kinect is essentially a VGA webcam (640x480) paired with a VGA infrared sensor/emitter array. When paired with the proper software, this not only allows it to detect objects in 2D, but also depth and motion in 3D.
Basically the ps2's eyetoy is rubbish, the kinect has a greater recognition and smoother gameplay, which is understandable seeing as the eyetoy was released in 2003