"The traditional mouse enables the positioning of a cursor in a 2D plane, as well as the interaction of binary elements within that plane (e.g., buttons, links, icons). While this basic functionality is sufficient for interacting with every modern computing environment, it makes little use of the human hand's ability to perform complex multi-directional movements. Devices developed to capture these multi-directional capabilities typically lack the familiar form and function of the mouse. This thesis details the design and development of a pressure-sensitive device called The Mole. The Mole retains the familiar form and function of the mouse while passively measuring the magnitude of normal hand force (i.e., ""downward"" force normal to the 2D operating surface). The measurement of this force lends itself to the development of novel interactions, far beyond what is possible with a typical mouse. This thesis demonstrates two such interactions: the positioning of a cursor in 3D space, and the simultaneous manipulation of cursor position and graphic tool parameters."