Well i once read of a record player that played records with a laser, it worked but the records had to be very clean as the dust and dirt wasn't moved out of the way (like a needle would). But lasers might be a bit ambitious, something hackable and close might be an optical mouse. Don't know how you would do that but i presume you might get some info on the surface if you looked at the data in the right way. You might need to use different light sensors and interface directly with them rather than the mouse it's self. Obviously this will only work on flat surfaces.