Kingpin

Begin the game using the command line parameter +developer1 (ie. kingpin.exe +developer 1). Now start a game, and during play press ` to bring up the console. Now enter the following codes:
god or immortal  God mode
give all         All weapons and items
give weapons     All weapons
give ammo        Full ammo
give cash #      Get # amount of cash
give health      Full health
give key(1-10)   Get key # 1-10
noclip           Toggles clipping