While playing, hold CTRL-ALT-SHIFT 
and type any of the following codes: 

Code                   Effect
---------------------------------------
bedouinprince        - Invulnerable
checkmatein2         - Complete the mission successfully
hesbackandhesgotagun - Unlimited ammo
deplikespudding      - Free-eye mode (navigate using CTRL + arrow keys)

Note: If you use these codes you won't be enlisted to 
new units, your Combat Prority won't increase, and you 
won't be able to learn new AI skills.