Here is a watch by Japanese designer Ryohei Yoshiyuki called the "Time of the Sky."  It is designed to help you tell the time by the color of the sky. Although I think it would be confusing, really, it is interesting and does offer those of us who prefer indicators for hours and minutes the option of seeing what time it *actually* is. (I'm thinking perhaps a sundial would be a tad cheaper.)

Link -via My Modern Met