Click on your city port, then rename it with the names below for the following results, remember, always press enter after typing in the code and it can be used an unlimited amount of times:

BonanzaCreek - 100,000 Gold

Linlithgow - Max. Tools

ParadiseCity - Max. Finished Products, as long as you have at least 1 of these items.

SiliconValley - Reveals Entire Map

MariaDeTule - Allows 100% Planting Area