We have seen quite a few different digital clocks here at Geeky Gadgets, the latest one is more of a puzzle designed for kids than a clock, the Manual Digital Clock.
As the name suggests, in order to get the clock to tell the time you have to change the display manually each minute, which would certainly keep you busy.
The Manual Digital Clock is designed to teach kids how to read the time on the clock, and they can interact with it by making the puzzle to display the current time.
If you want one, the Manual Digital Clock is available for $100 from Ponoko.
Technabob via Dvice via Gizmodo