Usefulness being subjective, of course.

Watch this video, about 50 seconds in:
http://www.escapistmagazine.com/videos/view/the-escapist-presents/639-World-of-Her-PWN-Four

About that time I was rolling on the floor too ;)

This is neat, I would suggest that if your Arduino runs on 5 volts just use the USB port on the PS2 to power it.

I liked Katamari Damacy, but the controls were not intuitive, they didn’t work like real tanks should, you needed to use all 4 axis, almost just to torture you. No real reason for it.

I wonder if you could hack up the control scheme of the game (using an action replay or gameshark) to use a single standard mouse plugged into USB (put all the programming onto the PS2 platform), or maybe even using the Playstation mouse.

I would love a beach-ball sized controller floating on an air base, perhaps with the right optics you could focus a mouse on the floating surface, you could position an IR break sensor below it, and pressing the ball down would activate the presses (I forget, what were the presses used for again?)

Also you could figure out a way to translate the inputs to one single mouse using logic. Basically reverse-engineering the software the game is using to convert 4 input axis into 2 motion axis, then putting that on-board the Arduino.

Also I have converted a standard PSX controller to have the left analog stick where the d-pad was, after I got Katamari I started wanting to move the left stick up to where the action buttons were, kinda like a handheld version of this: http://curmudgeongamer.com/2005/10/ace-combat-and-dual-analog-flight.html

PS, love the music, that game is freaking awesome.

could the background clatter be any louder? a toilet flushing in the background would have completed the soundtrack! give those people behind the camera a dope slap to the back of the head.