Metal Gear Solid 4: Guns of the Patriots Cheats

Completion Unlockables
Big Boss Extreme difficulty: Complete the single-player mode once (and saving the cleared data).
New combat vests: Clear the single-player game once

Costumes
Altair: Obtain the Assassin emblem
Civilian Disguise: Start Eastern Europe level
Middle East Militia Disguise: Middle East in the Militia Safe House
South American Rebel Disguise: South America (Cove Valley Village)
Suit: Clear the game once

Otacon's extra passwords
Put these in instead of the code Otacon tells you to at Shadow Moses. You will get the Access Denied scene but afterwards you will get the bonus.

14893: 100,000 DP
78925: iPod song
13462: iPod song

Show Me Your Motions
When a character is introduced for the first time, press R2 to view that characters motion capture person instead of that person's voice actor.

Facepaint
Different face paint unlocked for in game use.

Big Boss's: Earn the Big Boss emblem on a single-player session
Crying Wolf: Defeat the Battle Beauty (human form) Crying Wolf by non-lethal means.
Drebin: Purchase and keep more than 60 different weapons.
FaceCamo: Defeat the Battle Beauty Laughing Octopus (the overall battle, no specifics involved).
Laughing Octopus: Defeat the Battle Beauty (human form) Laughing Octopus by non-lethal means.
Otacon: Shock Dr. Emmerich using the Metal Gear II during the intermission scene.
Raging Raven: Defeat the Battle Beauty (human form) Raging Raven by non-lethal means.
Raiden Mask A: Shock Sunny using the Metal Gear II during the intermission scene.
Raiden Mask B: Shock Dr. Naomi Hunter using the Metal Gear II during the intermission scene.
Roy Campbell: Shock Colonel Campbell using the Metal Gear II during the intermission scene.
Screaming Mantis: Defeat the Battle Beauty (human form) Screaming Mantis by non-lethal means.

iPod Tunes
Snake's iPod can download specific tunes throughout the course of the game. Some songs have an additional "secret" effect when it is played in the game.
Beyond the Bounds (increases stun damage done by Snake from non-lethal weapons): Stage 4 Shadow Moses, Tank Hangar. After power is restored, backtrack to the upper catwalk and explore all rooms
Big Boss (increase stun damage and increases Snake's accuracy when played): Earn the Big Boss emblem.
Bio-hazard (cause soldiers held by Snake to scream in terror): Stage 3 Europe, Midtown
Destiny's Call (cause soldiers held by Snake to go enraged): A random gift from a militia or rebel soldier if Snake gives them a healing item.
Flowing Destiny (cause soldiers held by Snake to weep like a little girl): Stage 4 Shadow Moses, Canyon. Before leaving the canyon area, examine the rocky walls for a hole hiding this item.
Fury, The (cause soldiers held by Snake to go enraged): Stage 2 South America, Cove Valley Village. Inside the fire ravaged house.
MGS 4 Love Theme / Action (cause soldiers held by Snake to weep like a little girl): A random gift from a militia or rebel soldier if Snake gives them a healing item.
Opening - Old L.A. 2040 (increase Snake's accuracy): Stage 4 Shadow Moses, Nuclear Warhead Storage B2. Input 78925 into Otacon's lab computer.
Policenaughts Ending (cause soldiers held by Snake to fall asleep on touch): Stage 4 Shadow Moses, Nuclear Warhead Storage B2. Input 13462 into Otacon's lab computer.
Rock Me (increases Snake's amount of life recovered from items and other means): Stage 2 South America, Confinement Facility. Island in the south-eastern quadrant.
Sailor (increases Snake's amount of life recovered from items and other means): Stage 2 South America, Vista Mansion. Between the east wall and a cargo container.
Show Time (cause soldiers held by Snake to scream in terror): A random gift from a militia or rebel soldier if Snake gives them a healing item.
Snake Eater (increase the life recovery rate of Snake through items and other actions): Unlocked by earning all 40 game clear emblems.
Subsistence (increase Snake's accuracy): Play at least one game of Metal Gear Online. You must start the match with at least two players.

Refill Psyche During Cut-scenes
If during a cut-scene something causes Snakes psyche gauge to decrease just press [X] rapidly to replenish it.

Dolls/Statues
You need to unlock 5 dolls before you can adquire the solar gun.

Defeat the Frog Soldiers, Laughing Octopus, Raging Raven, Crying Wolf and Screaming Matis with Non-Lethal weapons. (During their beast form, not beauty). After defeating them grab the doll before killing their beauty form. Except on the frogs because they don't have a beauty form.

Crying Wolf Doll/Statue: In a side of a bulding just where you start after killing her beast form
Frog Soldier Doll/Statue: At the garage at the end of the battle
Laughing Beast Doll/Statue: On a bed in a little room
Raging Raven Doll/Statue: On the upper floor on a corner
Screaming Mantis Doll/Statue: On the corridor where you started

Unlock Emblems
Ant Emblem - Shake 50 enemies for items
Assassin's Emblem - Beat the game with 50+ knife kills, 50+ CQC holds, and 25 or less alerts
Bear Emblem - Choke 100 enemies to death
Bee Emblem - Use the Scanning Plug S or the Syringe on 50 enemies
Big Boss Emblem - Beat the game on the highest difficulty with no deaths, no alerts, no kills, no recovery items, no stealth suit, no bandanna items, in under 5 hours
Blue Bird Emblem - Give friendly soldiers 50 items
Eagle Emblem - Get 150 headshots
Fox Emblem - Finish the game on normal or higher w/ no deaths, 5 or less alerts, no kills, no recovery items, no stealth suit, no bandanna items, in under 6 hours
Fox Hound Emblem - Finish the game on hard or higher w/ no deaths, 3 or less alerts, no kills, no recovery items, no stealth suit, no bandanna items, in under 5.5 hours
Frog Emblem - Dive or roll 200 times
Gecko Emblem - Press against walls for a total of 1 hour
Giant Panda Emblem - Complete the game after 30 cumulative hours of play
Gibbon Emblem - Hold up 50 enemies
Hawk Emblem - Get liked by 25 friendly soldiers
Hog Emblem - Get 10 combat highs
Hound Emblem - Finish the game on hard or higher w/ no deaths, 3 or less alerts, no kills, no recovery items, no stealth suit, no bandanna items, in under 6.5 hours
Hyena Emblem - Pick up 400 dropped weapons
Inch Worm Emblem - Crawl on the ground for a total of 1 hour
Little Gray Emblem - Obtain all 69 weapons
Lobster Emblem - Spend a total of 2.5 hours crouching
Rabbit Emblem - Look at 100 Playboy pages

Unlockable Extra Music
In Act 4, enter the following codes (once per game) to unlock more iPod ™ music:

78925
13462

Upon completing the game once, you will have the option to go into the EXTRAS menu and input PASSWORDS for more items. Enter the following codes for more iPod ™ music:

thomas
george
theodore
abraham

100K Drebin Bonus
When entering the password into Otacon's terminal, input 14983. Although incorrect, Snake will (invisibly) gain 100K of Drebin points. Run through the game a few more times with this and the no kills and no alerts bonuses, and you should amass quite a sum of Drebin points.

Online Friendlessness
Trying to find a friend on Metal Gear Online but can't? That's because a player needs to log into their MGO account (and onto a server) before you to find them. Additionally, you "add" their MGO character name to your Friends List (for Metal Gear Online only), not any other Playstation Network game.

Under-handed-ness
Throw your grenades under-handed by lightly holding the L1 button (or your aim button, if you changed your controls), instead of holding it down completely.

Big Boss Tips (Act 3)
For players who are frustrated by the hardiness of Extreme difficulty, here're a few tips for Act 3: Press Triangle during the bike chase to take cover behind Eva. She cannot die during the bike chase, but Snake sure can!

SOCOM Mk,23
Although you can enter a password to get the Heckler and Koch Mk.23 SOCOM pistol (handgun from the first Metal Gear Solid), you can easily pick one up from underneath the transport truck at Shadow Moses Island's Helipad.