Laser DRO ??

Hi gang,
I have been reading with interest all the posts on the digital
readouts and just had a thought. Has anyone thought of using the
laser mouse for a cheap DRO? These work on almost any surface and
seem to have a fair resolution but would the resolution be great
enough for the task at hand! I have one pulled apart that was fried
in a power surge (along with the rest of my computer) and there
isn't much to it.
Just a thought and what do you all think?
Rich.