Just wanted to let you know guys that PS/2 to USB adaptor are actualy working with Playstation 2 system. It work perfectly with Socom 2 right now but I'm having some issue with it when playing FF XI. It work and then all of a sudden, the last key used is repeated a million times and you have to unplug an re plug the adaptor to make it work again.
I bought it at Radio Scrap for like 14$. Here is a picture of it if anybody want to try it out on their PS2:
PS/2 to USB Adapter