My job.

This little sphere and the stylus next to it, is what I've been working on for the last month and will be working on a lot more, since it is part of my daily job.
The sphere on the left is about 24.9943 mm in diameter (@ 20 degree C) and it's used to qualify the touch-stylus on the right, just to make sure whatever you try to meassure is as accurate as possible.