I have always of course been partial to my own True Binary Clock, but I recently came across another based on the same idea, but with pretty graphics (and sound!):

This is the Steampunk Binary Clock from ruinsofmorning.net. Very cool, although I’m not so hot on the idea of grouping all eight middle bits into “minutes”, I prefer counting each group of four bits seperately.

Also of note at the same site, the HexClock, which is basically the same sort of thing again, but showing the same 16 bit version of time as four hexadecimal digits, which is actually quite nice. (He still groups the middle two bits though.)

I would buy a physical version of my clock, or either of these two clocks in a heartbeat if someone was selling them.

Very cool.

[Edit 07:48 UTC to add the parenthetical statement and fix some punctuation.)