A method of controlling movement of a cursor of a video display comprising steps of: providing a hand-holdable device having a two-dimensional array of photosensors; tracking movement of said device relative to a region of an environment in which said device resides, including substeps of: (a) periodically forming largely overlapping images of a field of view of said array; (b) storing a first image as a reference image; (c) correlating said images such that changes in location of characteristics of said region within successive images are computationally recognized; in response to said substeps (a), (b) and (c), forming a cursor-control signal that corresponds to computational recognition of said changes in location; and transmitting said cursor-control signal to said video display. view more