The Little Magic Balls - New Technology for Aided Navigation
The German company Advanced Realtime Tracking developed a set of small spheres which permit their tracking and, therefore, to be used as a reference for attitude and position calculation. http://www.ar-tracking.com/products/markers-targets/targets/passive/
What draws the most attention to this technology is that, despite being totally passive, their reflectivity make them seem to shine out of the visible light range. See the photo taken from a digital camera without flash in low light environment.
The such "balls" shine as by magic. This allows tracking them by various forms of light emission, including laser.