Cheat Call of Duty 4: Modern Warfare

Cheat Codes (DEMO VERSION)
Enable the console from the game's in-game options.
Hit the tilde key (~) to drop the dev-console.
Type seta thereisacow "1337" and then press ENTER.
Type spdevmap bog_a and then press ENTER.
This will start the demo with cheats enabled.
When playing, drop down the dev-console and enter
the following codes and hit ENTER to activate or toggle them.

Cheat Codes (COMPLETE VERSION)
Same as above but after you load up the spdevmap bog_a exit out and load the level you are currently at, or a new game.

You can not select "resume" and have the cheats function you can however select the map/act you want to start at with the cheats enabled.

Effect	Code
Access All Weapons	give all
Add Laser Sights to ALL Weapons	cg_LaserForceOn 1
Adjust Gravity Default = 39	jump_height #
Adjust Time Default = 1.00	timescale #
Allows you to shoot without reloading.	sf_use_ignoreammo 1
Easier to see things	r_fullbright
Enemies Ignore You	notarget
Full Ammo	give ammo
God Mode	god
God mode but screen still shakes	demigod
Kill player	kill
No Clipping Mode	noclip
Removes all your guns and health	take all
Removes your ammo	take ammo
Removes Your Gun	cg_drawGun
Same as noclip?	ufo
Set player's sprint speed	player_sprintSpeedScale
To draw the light emitted from the laser	cg_laserlight 1
Zoom with any Gun	cg_fov

Sumber : www.gamefaqs.com