I needed to strip a bunch of ribbon cable leads, and stripping each wire individually by hand was a real pain. Looking around for any quicker way of doing the job, I read about laser wire stripping. Turns out it's a standard technique for accurate stripping. What's more, it's ideal for ribbon cable. Here's one site with some good information and photos - http://www.laserwiresolutions.com/. They have an imgur album at http://imgur.com/gallery/assPb. The fancy machines can even do tricks like using different wavelengths of laser to cut different layers of the insulation (if there are several layers present).
I did it by using the laser to cut across the ribbon cable, with some lines lasered on to a piece of card to help position the cable. I did it from both sides to ensure the insulation was cut right through. The laser naturally doesn't mark the wire itself at all. Here's some photos of the result (the last one is actually from Laser Wire Solutions, but I mirrored it here because it looks really cool):
Here's a video of the process: