Ironic Sans has one of the coolest ideas for a clock ever: it's a sundial! Well, OK, those have been around a while, but his idea is to have two light bulbs which circle the central post (called a gnomon). One goes around every hour, and the other goes around every minute. They are at different distances from the face of the clock, giving two different shadow lengths, and the shadows mimic the hands on a clock. Very cool.
in the comments, I added that using LEDs would make the shadows darker, and give you better shadows in a more lit room, and a cowling over the face would prevent other lights from interfering.
I seriously think this is a cool idea. I wish I could make things with tools without severing off fingers, because then I'd try it.