Mouse-tracking has been especially useful for assessing the temporal dynamics of mental processes, for revealing "hidden" cognitive states, and for fleshing out real-time interactions among mental processes. It's also uniquely appropriate for testing motor/spatial effects. Anything's possible, though. There's a lot of rich information revealed in the moving hand and MouseTracker could be very useful in many domains across experimental psychology, cognitive science, and beyond.

For more information and published mouse-tracking studies, please see my research and that of other researchers, Rick Dale and Michael Spivey.

Also, our 2010 article in Behavior Research Methods has an introduction on the mouse-tracking method.