The ToolStone is a cordless, multiple degree-of-freedom (MDOF) input device that senses physical manipulation of itself, such as rotating, flipping, or tilting. As an input device for the non-dominant hand when a bimanual interface is used, the ToolStone provides several interaction techniques including a toolpalette selector, and MDOF interactors such as zooming, 3D rotation, and virtual camera control. In this paper, we discuss the design principles of input devices that effectively use a human’s physical manipulation skills, and describe the system architecture and applications of the Tool- Stone input device.