Regular travel makes a laptop a constant companion. What is also constant is the use of the little red nub tucked in the middle of the keyboard because you did not have the space in your fancy laptop sleeve to carry one. Well if your laptop has a PCMCIA slot, then the G4 mouse can provide you with an external mouse that doesn't take up any room when it is not in use.
Once you need it, just pop it out of the slot, pull out the USB cable and fold it into a shape more closely resembling that of a mouse. Based on the pictures, it looks a bit suspect when it comes to comfort, although we can see an improvement over using the standard red nub for hours at a time.