Recently, the measurement of computer-mouse trajectories en route to choices on the screen has served as a window into the real-time dynamics of a wide range of cognitive processes. This mouse-tracking methodology is able to provide a sensitive, temporally fine-grained measure by which participants’ tentative commitments to various choice alternatives can be tracked semi-continuously over hundreds of milliseconds. Similar in spirit to the goals of eye-tracking methods, mouse-tracking may provide access to the micro-structure of perceptual, cognitive, and social decisions. Though both methodologies have their strengths, one advantage of mouse-tracking is that it relies on continuous streams of hand motion rather than discrete saccades, and it does so with nominal cost---needing nothing more than a computer and mouse. These qualities led Magnuson (2005, p.9996) to comment that “the mouse-tracking technique [has] the potential to address not only specialized theoretical debates but also some of the biggest questions facing cognitive science.”