1. A system for an electrical tissue stimulator coupled to an array of electrodes, comprising: a user-controlled input device configured for generating control signals; and at least one processor configured for generating a plurality of stimulation parameter sets in response to the control signals that, when applied to the electrodes, will shift electrical current between the electrodes to modify a region of tissue activation, the at least one processor further configured for computing an estimate of the region of tissue activation, and for generating display signals capable of prompting a monitor to display an animated graphical representation of the computed estimate of the region of tissue activation.