Glashütte’s Nomos rings are clever little fidget-rings that act as sundials: you adjust the little sliding rings to the correct date, turn it to the sun, and the shadow cast by the little ring tells you the time.
Each city (or at least, all cities at the same latitude) needs its own ring; right now the company does Glashütte, Germany (its hometown), New York and Madrid. The rings are $185 in stainless steel, $310 plated in 23K gold.
(via Wired)