Some of the Civs seem to have rather weaksauce abilities, perhaps worthy of being modded into awesomesauce abilites. This one occured to me on the way home today: America: American Dream Cities with a Trade Route gain +10% Population Growth. This reflect's America's history of immigration from Europe and the promise of the Land of Opportunity. I'd considered other possibilities, such as cities gaining +5% growth for every Civ involved in trade of strategic or luxury goods, or a bonus to growth that kicked in when Harbours were built. But this seems relatively simple. Any other ideas?