I built a small device that can measure distance by only using a webcam and a laser pointer.
The whole idea is based around a paper by Todd Danko.
In addition to that I wrote a little piece of software that controls the device and gives you a visual representation of the results.
I did this in february 2016, but I have discovered steemit in the meantime and there is a second part coming up soon, so I thought I might share it here as well :)