Undated -- The windmill may be Pete Townshend's signature move, but it's really Keith Richards' move. Townshend writes in his new autobiography, "Who I Am," an early version of the band called The Detours opened for The Rolling Stones in December 1963.
Townshend saw Richards swing his arms like a windmill to warm up. When they opened for The Stones a few weeks later, Richards didn't do that, so Townshend adopted it for himself. A month or so later, they found out another band had the name The Detours, so they needed a new name. The name "The Who" came from future Who biographer Richard Barnes. Townshend himself wanted to call the band "The Hair."