You just can't throw that away...
As a day-to-day commuter bike, I ride an old Fuji S10-S, which I estimate is about 30 years old. It's a steel frame, and kind of heavy, but I keep it in good shape and love it.
The other day, a few teeth fell off the rear freewheel (yes, freewheel; this bike is older than cassettes). I wanted to keep riding my bike, but I didn't want to put some modern part onto it. Luckily, my friend Ken who owns Syklo (the best bike shop in Charlottesville) specializes in vintage bicycles, and was able to find another 6-speed SunTour freewheel from about the same era.
So, we put it on, and after a few repairs my Fuji is riding as good as new. But then the question arises: what should I do with the original freewheel? It was such a quality part that lasted for thirty years, how could I throw it away?
My solution was to immortalize the part as the base of lamp.