From the chat line (press m to bring it up) type in:

dangerous	- unlimited ammo  
chump		- invincible (type chump twice to become a super tank)
chumpchump	- God Mode
slick		- God Mode

tuff		- enables you to destroy buildings.
mo money	- extra troops
way mo money	- extra powerups

Thanks to Revolution readers Max Harrison, Bob Mayfield, Motiv8, Michael Staples,

Gabba, Ashley and DMK!