On the 15th day after its landing on Mars, Curiosity exercised its wheels for the first time. First it rotated all wheels out (pointing radially away from the rover's center), then in (the direction they must point for a turn in place), and finally straightened the wheels, making the rover ready to drive the following sol.
Top left corner: Navcam image of the right rear wheel. Top right corner: Hazcam image of the left rear wheel. Bottom left corner: Navcam image of the right front wheel. Bottom right corner: Hazcam image of the left front wheel. The rover actually tested each of these wheel motions one at a time; the motions are condensed into four frames here for clarity.