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