I work for a company (linked in my sig) that does Stereo Cameras. Stereo cameras allow machines to do exactly what you're hoping to do with this custom laser jig, but all in one nice and tight package. Here's a simple breakdown on how it works:
1. You know the distance between your camera's two lenses.
2. You can "measure" the distance between two features in an image.
3. Since you know the distance between lenses, the the distance in pixels between two features, through calibration you should be able to identify and quantify the distance between features. One "difference" is called a Disparity.
4. Using a nifty, already developed piece of software called SVS (credit to this goes to SRI's vision lab, more specifically Kurt Konolige, my boss), you can lay out an image that plots all Disparities in color to represent the depth and distance. A good example can be found here
http://www.videredesign.com/index.php?id=65 if you're curious.
Vision is awesome, and can do just as much (if not more!) than some laser systems.
If you're hooked on lasers, go check out Hokuyo Automation's products. We use some of their laser rangefinders for our SLAM bots. They're a little pricy for FIRST, but man oh man are they cool.