The Gee Haw Whimmy Diddle
is an Applachian folk toy consisting of the Whimmy, a notched stick with a propeller on the end, and the Diddle, a stick rubbed over the notches on the Whimmy.
If you have "the power", you can make the propeller spin left or right, seemingly on voice command. Gee and haw are voice commands given to horses or mules to cause them to walk slightly to the right (gee) or to the left (haw) when pulling a plow. Thus saying "gee" or "haw" while manipulating the Gee Haw Whimmy Diddle causes the propeller to spin to the right or to the left. It drives those without "the power" nuts!