To activate the cheat mode (an "Extras" menu), type CTRL A O D B A M F in sequence at end turn. The menu contains the following cheats: ScaleIt : Increases your production.
ArmyInfo : See information about the other races.
MoneyAndPower : self-explanatory.
AllSeeingEye : Reveal the whole map!
GetRichQuick : self-explanatory.
GetSmartQuick : self-explanatory.
MissileCrisis : Creates the production of nuclear missiles.
SettlersHo! : Creates settlers.
Nukestorms : Causes Global Warming.
Automode : The computer moves for you.
Armaggedon : Nukes the whole world!
If you pressed Ctrl A O D B A M F you can also click with the right mouse button on a the map to create units. When you click you get a kind of menu from which you can choose a unit to create. It is possible that it does not work. There are two possibilities: 1 the area you clicked on is not yet discovered (it is black when the "AllSeeingEye" is disabled) 2 you have to many military units (message:"Sire, our people cannot support so many military units) If you play a hot seat game don't press Ctrl A O D B A M F unless you want to nuke all your cities (not the ones of the other civilisations).