digitizer from a mouse?

Hi,everyone,
I've being thinking about make a 2 axis Digitizer from a mouse
encoder.
it would use the mouse input and have two axis,kind like a manual
gantry with a probe and the encoders atatched to the x and y
axis,movement would be done by hand and the points into xy
coordinates to rhino.
it would take cross sections lines or points from the object and
than via the mouse input it goes to the cad software.
Anyone has tryed that?
open to coments.

fogassa.