Easy Mouse Lock is, without doubt, an original utility to apply to the mouse. It lets you define set co-ordinates on the screen and from then on the mouse cannot leave that zone.
To define these co-ordinates you have to indicate the height and width, for example, 100x100x200x350 pixels. With this the mouse can only move in this rectangle and it is impossible to exit both the rectangle and the program.
To escape from these settings just press Esc.