well playing with the emulator fps and angle value and comparing it to the fps and angle value of the nexus one, I obtained a simple y=mx+b equation assuming the angle/fps has a linear relation.
camera.rotateCameraAxis(m.invert3x3().getXAxis(),
-line.length() / (((10/45)*fps) + 25))
It seems to work fairly well in the nexus but I guess I'll have to test in in different devices.
Maby you can think of a better way ^_^