Forget hands rotating around a dial or numbers flicking in the dark; this whiteboard-mounted clock erases the time every five minutes and writes the new time. And it's kind of adorable to boot.
Maurice Bos has written up the documentation for this little guy, in case you want to build one of your own. Bos currently has it set to change the time every five minutes, but it can be set to different rates. It may not be an entirely new idea (Core 77 points to a far less entertaining whiteboard clock), but it is pretty fun to watch the clock in action.