This wristwatch from ThinkGeek may not be the most practical of timekeeping devices, but it’s certainly creative nostalgic. The “flux capacitor” section contains 12 lights. To check the time, you press the button and count the number of lights that flash on. The watch flashes three times to indicate hours, the first digit of the minutes, then the second digit of the minutes.
There’s also a date display in a familiar looking font, though you can press another button which will “activate the flux capacitor” and then display a random date.