Monteverde One Touch Tool *, a fountain pen with several functions built-in, is the first of its kind that I have ever tried. My first impression was how streamlined the pen looks, the metal body (seems like brass) is spray painted silver and it's hexagonal through out with minimal obstruction. There four rulers integrated into the body: 1/100m (standard metric), 1/200m, 1/300m and one in English system.
The two sides left are occupied by a level and a clip that's stiff but springy enough to be easily attach to shirt pocket. Just keep in mind that the pen is heavy, long (might not fit shirt pocket) and the nib will be facing down (leaking potential).