I watched one of the live broadcasts they did about a week before launch and they mentioned that there was going to be a tweaker or something to that extent that people would need to enable in a config file before it was used. It sounded like this would function similarly to the world builder in civ4. However I didn't see anything on a cursory look in the folder and I know a world builder isn't available yet- so alternate methods might be available when that's released, but my guess would be we'll see a trainer first anyway.
Edit: in Documents\My Games\Sid Meier's Civilization 5 theres a usersettings file that has a debugmode=0 line so changing that to 1 might give some options I'm gonna mess around with it I'll post if anything works
That's what I edited it with as well, it was plain text for me. The first thing that comes to mind is maybe if you're playing the demo? I got my version through steam, but don't think that's the difference..