Metal Gear Solid 2 - Sons Of Liberty cheats and cheat codes for Playstation 2

Infinite ammunition
Find all dog tags and finish the game and save. Begin a new game 
and equip the wig you have unlocked. You will get unlimited ammo 
and you don't ahve to reload.

Blue title screen and Extreme mode
Finish the game once

Increase grip strength  to level 2
Press L2 + R2 minimum 100 times when hanging on a ledge to 
do pull-ups

Joke code:
Quickly press Up, Up, Down, Down, Left, Right, Left, Right, X, Circle 
at the clear code screen. You will hear Snake yell, but the code 
(the classic Konami code) does nothing. 

In-game reset:
Hold L1 + R1 + L2 + R2 and press Start + Choose during game play.