When inside a game waiting room, press L1, R1, L2, R2, L1, R1, L2, R2, L1, R1, L2, R2, L1, R1, L2, R2, L1, R1. If you entered the code correctly, you will hear a sound. From now on, chat can be accessed by pressing Square inside any game's waiting room. This code must be reactivated after you reset or turn off your PlayStation 2. Note: Press Square to open/leave chat for that game room. If there is a new message and you are not in the chat, you just press Square again. To summarize, press Square after the code is enabled to make a keyboard appear where you can chat. Press Triangle to exit the chat, and Square to re-enter. Incoming messages will appear in the bottom right of the screen.
Invisibility
Press Left(2), Down(2) during game play for short term invisibility.
Shield
Press Right(2), Down(2) during game play for a short term shield.