In this video the effect has been sped up for clarity, however the same effect could be had with a high torque clockworks using the minute and second hand. I enjoy the subtle effect of using the hour and minute hands myself. Not sure what youtube did to the color in my video.
A moire pattern is caused by interference, more information is available here moire at wikipedia
Step 1: Gather your materials
A clock movement
assorted odds and ends
Start by removing your clock movement from a clock. Place your thumb against the time setting knob and gently twist off the hands, then unscrew the nut around the shaft, the movement should now be free. be sure to save the hands.
Step 2: Creating the moire pattern
Step 3: Making the dials
Once printed the photo paper dial will need to be reinforced by gluing, with aerosol glue, to a piece of thin cardboard.