All Maps:
At the menu screen, enter LEFT, LEFT, RIGHT, RIGHT, A, B, LEFT STICK, LEFT STICK.
Climbing Glitch:
On some levels, especially ferry boat, you can climb on chairs and stuff to get in good spots. Get parallel to whatever you want to climb on and click the left Thumbstick really fast.
Credits level:
Click Left Analog-stick(2), click Right Analog-stick(2), press X, Y, B, A, B, A at the main menu.
Garbage Man:
When on X-Box Live on the map Agora there is a balcany with 2 garbage bags.(one is big one is small.)walk(or run)into either of them and crouch you should look like the garbage bag.(be careful your gun may stick out and many people may know this glitch.) THIS ONLY WORKS ON ADVERSARAIL MODES!
God mode:
Press Up(2), Down(2), Left, Right, Left, Right, B, A during game play. The message “God Activated” will appear to confirm correct code entry. Note: This only seems to effect you, and not your team or hostages.
Hall of Fame:
At the main menu press: Left Thumb Stick, Left Thumb Stick, Right Thumb Stick, Right Thumb Stick, X, Y, B, A, B, A.
Wall of Fame Map:
At the menu screen, enter LEFT STICK, LEFT STICK, RIGHT STICK, RIGHT STICK, X, Y, B, A, B, A.