Rick has made a nice looking hard drive clock with good instructions on how to build your own!

“This is a hard drive clock that requires only a power drill and some basic hand tools. No electronics knowledge is necessary. Total project time: 60-90 minutes.
Supplies:
* Old hard drive (duh). I happened to find a 5.25″ model while working at FreeGeek. Smaller or bigger drives could be just as fun.
* A clock movement from your local craft&hobby store. Get the one with the longest shaft you can. Mine was 3/4″ and it fit perfectly.
* I used a bit of old IDE cable to help support the bottom of the clock. You may need to get creative to get yours to hang parrallel to the wall.
* A six pack of your favorite beverage to celebrate your cool looking clock.

Tools:
* Hand drill with bits up to the size of the clock movement shaft. I needed a 5/16″ hole for mine.
* Various screw drivers, perhaps with hex or torx bits, depending on the model of your drive.
* A hammer
* If you do the IDE cable trick I describe, you’ll need a utility knife (or sturdy scissors) and some hot glue.”

Via: Make