Hi,
I've written a simple sketch that polls a Playstation controller. It is compatible with Dual-Shock 2 controllers (including mini-sticks and pressure buttons).
Information: http://www.wegmuller.org/arduino/Arduino-Playstation_gameport.html
The first application is a Lego walking dragline.
Pictures here: http://wegmuller.org/v-web/gallery/Lego_Walking_Dragline?page=4
I'll add a movie soon...
Greetings,
David