Most portable computers have a trackball device included on the keyboard. It uses less space than a mouse and won't get lost as easily. Well you did not buy a computer just for work. The arrow keys on your keyboard can be used, but it's a joke. A mouse might do, but it's clumsy.
Games are heavy users of joysticks.
You can control motion better when moving around Arcade type games. The feel is more realistic not to mention a better chance to score points. Comments and suggestions are gladly accepted. Simply email me.