Leave the domino effect to books, people, and, well, real dominoes. In Carbon Design's Domino Clock, the black dots silently switch to white dots to indicate the time, functioning similar to a digital clock (except with oversized dominoes).
A custom actuator was designed to power the thousands of transitions the dots make each day, and the only time power is used in the clock is when those transitions are made (kind of like epaper devices).
The individual dominoes of the clock communicate wirelessly to correctly display the time, and they can hang on a wall or stand freely. [Carbon Design]