There IS a reveal map cheat, of sorts. If you start a game and then wait two or three turns (allowing all of the AI civs to build their first cities) then save the game. After saving, retire. You will suffer a humiliating defeat, BUT the powergraph will pop up showing the history of all the civs AND what the map looks like, not in detail, but you WILL see all of the continents, you can sort of see where jungle/hills/prairie are vs. desert/tundra/floodplain and you can see how close continents and islands are to your continent. You also now know where the other civs are in relation to you. Then you can reload your saved game and POOF! You know the map (roughly) and your score isn't affected!