If you have ever repaired a desktop personal computer, you probably recognize the picture to the right. It's a standard PC cooling fan, and you'll find them in all shapes and sizes inside PC power supplies, on that beloved Intel dual-core CPU, or on that massive ATI graphics rig in that system.
If you're into collecting spare PC parts,
or would like to visit a local PC repair shop for a $10 purchase, you can turn that cooling fan into a neat clock with a virtual readout using red and green LEDs (or any other LED color of choice).
You'll need some actual or fabricated clock hands to install on the top of the fan apparatus itself, along with a few LEDs that will serve to push those chosen colors in a strobe fashion as the fan spins. You'll also need a 12-volt power source for powering the fan (or an AC adapter) and some transistors as a power source for the LEDs themselves. Check out the full deets here, and if your electronically savvy, this'll make a cool autumn mantle clock
for above that fireplace -- right?