I have this crazy idea to stick a joystick on a mouse, basically need a simple 4+ button stick and a simple + 4 way hat, figure out best placement of the stick to hot glue on the mouse then wire up the mouse to the stick. Only trouble is I am not sure if I will need any kind of control device, prob will need one for the hat so it can do a tilting scroll wheel, the buttons can easily be soldered in on the cheap. It beats spending 110$ just for the lulz of it.
All the mouse does is send X and Y coordinates to the computer for it's positioning.You can build one with two potentiometers.Most older mouses have 2 encoder wheels inside that are pulse counters. http://www.slagcoin.com/joystick.html