PlayStation Move takes up very little memory
One of the PlayStation Move demos at GDC shows full body tracking using an on-screen body puppet. It does it by combing the Move and the PlayStation Eye. The PS Eye can detect faces, even recognize gender, age, smiles and if your eyes/mouth are open or not. There isn’t a video that I could find of this exact demo. But it sounds pretty similar to this post I made back in September 2009.
Coombes explained that all the calculations necessary to handle image processing are done by the Cell CPU, which apparently excels at the doing floating point calculations. The raw data can be processed incredibly quickly by the PS3, taking “under a frame” to translate to a game experience.
It does all that with only using 1-2 MB of system memory. Pretty impressive.