I've had this idea for a while now so I finally decided to try and throw it together. The idea is this: a clock that tells time in reduced fractions. For example, think of the time 8:18pm as the fractions 20/24 : 18/60. So we're on the 20th hour out of 24 hours total, and the 18th minute out of 60 minutes total. Now reduce both of those fractions to their simplest form and you get 5/6 : 3/10. It might seem nearly impossible to read and pretty impractical, but it does give an interesting new perspective on time (e.g. "3/10ths of the hour have just gone by"). Anyways, I coded up a little java applet that does exactly this, which you can check out here (you'll have to click "run" and it might take a second to load). Go take a look!