Ben Heck completed this fully functional PSOne Portable in September, 2001. As one of his first portable gaming creations, it consisted of a Casio EV-550 screen, PSOne internals, memory card slot, 2nd player controller port, and a custom-built case. Short video demonstration after the jump.
In the end the project cost about $400 to create, half of that just for the screen. The buttons were all custom routed by me, except the original analog control knobs and the red “Toggle Analog” button, which was from Radio Shack