The Mars Exploration Rover engineering team had a problem...
A day on Mars is 24 hours and 39 minutes long. Dealing with the needs to align the team to Mar's solar day, they contacted a local watchmaker to create the very first Martian Watch. Due to his inability to produce only a few digital timepieces with the extra 39 minutes for a reasonable cost, he experimented by manipulating a traditional mechanical watch by slowing the watch down with weights.
It seems a missed opportunity by what could have been a much more interesting design in the end. I think the JPL should approach an appropriate watch company (or vice versa, they're busy!) to produce a mutually beneficial and aesthetically desirable timepiece for dual Earth-Martian time. I'm sure there are enough geeks out there who'd buy one. At the same time, there is more charm to this story as told in the article and video below. A bit more of the NASA spirit. What am I talking about? God, blogs are silly.
Jet Propulsion Laboratory Article
Video about the watchmaker from Discover Channel