Clouds make great hyperstereo subjects using a 200 ft or greater baseline.  Clouds change quickly,  so the photos must be taken at nearly the same time.  This shot was out of a sunroof using two cameras at ~50 mph with a two second separation.  If one waits for clouds to blow by the swirls change significantly.  Radio controlled cameras, aircraft views, and faster cars are all suitable alternatives.

crosseye view
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