User stream (Webcam) + WebGL
HTML5 is full of surprises these days! I had no clue that there are browsers out there that already support user stream (i.e. webcam). This was always something missing in HTML5 compared to what Flash could do.
To run the demo above you will need Chrome Canary with MediaStream flag enabled (detailed instructions can be found here). I was also able to run this demo in Opera Labs Camera build, which you can grab here. In both cases the performance was great!