This is a prototype of some improvements to the Circular Scrolling gesture provided in the X.org synaptics driver. For a proper introduction, see "Improvements to Circular Scrolling in Synaptics driver" in the xorg-devel@lists.x.org mailing list.
Move the cursor around within the "touchpad" region and watch the output. Vary the center, radius, direction, shape, and speed of rotational movement to see how it responds. It works best with an actual touchpad, because mouse control doesn't provide the same dexterity as a finger. This prototype does not implement edge detection, and does not respond to button state.