Abstract: A self-contained electronic unit includes a physically manipulable housing such as a mouse, a feedback device, and processing electronics. The housing is constructed to be moved in its entirety during use by a user. The feedback device is incorporated into the housing and is configured to communicate, to the user, movement of a virtual object within a virtual environment. The processing electronics are incorporated into the housing, and are configured to generate the virtual environment, to respond to movement of the housing in its entirety, without regard to relative movement of the housing with respect to any stationary attached hardware, by causing movement of the virtual object within the virtual environment. A trackball is contained within the mouse housing, and the processing electronics are configured to respond to direct physical manipulation of the trackball by a user to cause movement of the virtual object within the virtual environment.