Abstract: A system including a personal computer (1) and a display (2) is usable by at least two persons (owner 3 and customer 5) in connection with an application which does not support multiple mice or multiple cursor presentations. Each person has a respective mouse (4,6) and the customer is permitted to participate in the operation of the application, at least to the extent of being able to point to objects on the screen by means of a cursor, rather than having to point with a finger etc or communicate verbally. This is achieved, without needing to modify the application, such as by loading appropriate mouse driver software into the personal computer in order to generate an auxiliary cursor for the customer, or using appropriate mice hardware/firmware/software, so that the customer's mouse can control the owner's cursor when required.