I recently ran across the 32060 Technic Gear Timing Wheel 8 Tooth element when sorting a mixed bag of parts.
This element doesn't appear in many sets as a functional element. Here's one example from the Barcode-Multi-Set (8479) set:
What is the purpose of this element, and how does it work? I'm guessing from the name that it has something to do with timing. Perhaps it is used as a rotary encoder somehow?