Abstract: Pocket and cup sails formed from flexible materials, especially such sails formed with excess material, have spar like supports attached at their deepest point to maintain the depth of the said sails when the wind fills them so that the sails expand to maximize resistance to the wind coming into the openings of the sails and so that the sails deflate when the wind is coming from the back of the sails to minimize resistance to the wind, the said sails being attached to rotor arms on rotary devices to provide torque, the torque being used to rotate decorative structures including the sails themselves, generate electricity, bring airplane tires up to speed before landing, and/or measure wind speed, and sails optionally having cuffs on the inside to help the sails inflate and/or maintain inflation by minimizing spillage of air.