A computer input device such as a game controller is shaped to fit within a user's gripped hand. The user's thumb (92) rests on a top sloping wall (31) and can control buttons (1 to 3). The forefinger (93) and middle finger (94) are located in indentations (331, 332) in a front wall (32) and control buttons (4, 5). The thumb (92) may instead control a tracker ball (Fig. 7). The input device is compact, can be gripped by a single hand and requires no flat surface.