Mats writes –

This is a simple clock that shows the time (hours/minutes) in binary using leds hidden beneath glass marbles.

For an average person it looks just like a bunch of lights, but you will be able to tell the time by just a quick glance at this clock. It might take you a couple of days to get up to speed on the esoteric art of fast binary counting, but you’ll be able to tell the time right away, just a bit slower in the beginning.

HOW TO – Make a binary marble clock – Link.

DIY Binary clock project & binary clock roundup! – Link.