[highlight]It's probably doesn't actually use a laser - I took apart a broken laser mouse, to be met by a cheap but bright LED.... Though, a proper, nice mouse from Logitech might be different - I'm guessing, since my Logitech one is at 848nm too, and claims to actually use a real laser...
You probably won't be able to use a PHR-803T because of the difference in wavelengths. The mouse's CCD will be fine-tuned to run at its diode's wavelength, and other frequencies may even be filtered out to increase sensitivity. Also, I may be wrong, but even if the CCD could detect it, the difference in wavelength would make the speckle pattern very different compared to the other one.
You could probably set up a miniature second laser using an independent regulator shining onto the desk, to create your glowing effect, though. Shouldn't be too hard, if you're prepared to cut it open and operate on it, but you'd need to run at low power to keep it cool. Even then you run the risk of smoking your desk (MDF is really easy to smoke) and destroying the mouse. Smoke on micro lenses near sensitive sensors is to be avoided..[/highlight]
Sounds like a great idea, the mouse is real easy to take apart, and it's a laser (confirmed with ax. mod. and night vision) and i just got the logitech VX Nano so i got a backup if i screw it up...thanks for the input