To activate cheat mode, press CTRL, A, O, D, B, A, M, F at the end of your turn (do not hold down CTRL.) If you did it right, a menu will appear.

Here's a list of options and what they mean:

ScaleIt - Increases your production
ArmyInfo - See information about the other races
MoneyAndPower - Money and some units
AllSeeingEye - Reveal the whole map
GetRichQuick - Get Money
GetSmartQuick - Get Tech
MissleCrisis - Allows the production of Nuclear Missiles
SettlersHo! - Creates Settlers
Nukestorms - Causes Global Warming
Automode - The Computer Moves For You
Armaggedon - Nukes The Whole World