Similar in function to the more economically priced Planisphere watch, the Astrodea Celestial Watch designed by Hideo Uehara is a celestial aid for the visible sky. The Astrodea has 90% of the visible sky for parts of northern hemisphere, and it features cool styling and a waterproof case as well.
The watch can provide Equinox Indications, Sunrise/Sunset, Daily Duration of Sunshine, Meridian, Ecliptic, Celestial Equator, Boundaries of Constellations, and more, so it definitely fits into the “tool” category. The $599 price includes a 10x magnifier for easier viewing. I personally like the generous 42.5-mm anti-reflective Sapphire face, after all this is a lot of information. You can find the Astrodea Celestial Watch at ThinkGeek and other retailers.