You jest, but I ended up getting a lot of use out of being able to do this in software for a dimmable LED lamp. Dimming the LED required PWM, and the potentiometer resistance -> PWM frequency map ended up fairly intricate to make the knob "feel right."

Now what I would have loved to have done is come up with some crazy analog circuit to implement an arbitrary transfer function from potentiometer input to LED voltage, but I didn't know how to do this at the time and the dev cycle would be a lot more painful than with software.