Probably you noticed several digitally controlled analog meter clock. These are cool stuff. Anyway analog meters are close to real mechanical clocks in their appearance. What if make clock linear where hour and minute numbers are aligned as in ruler?
Euphy has built one that looks very similar as ruler, but if you look closer you’ll find two markers sliding along indicating hours and minutes. He put some work on it especially on mechanical side. The clock is controlled by Arduino and Adafruit motor shield, that takes care of two DC motors moving hours and minutes markers. Thumbs up for great idea!