Around Summer 2010 I was attending CVPR 2010. There was a guy in the demo area showing some image processing algorithms he developed and he was using an N900. It involved using the front-facing camera to perform face recognition for some security application but I recall he was getting extremely good quality out of it and great framerate (around 30 fps). It's a shame I didn't ask him the details but this was so long ago.

I was with a fellow colleague of mine (and n900 owner at the time) and even he was surprised at the quality of the front camera. He was the one who brought it up.