The Urbz: Sims in the City Cheats

First you need to earn $1,000 Simoleons.
Now start a two player game and create a new character to play with yours. Give this new created character $1,000 Simoleons. Have your main character walk somewhere real far doing something else. Now tell your newly created character to give your main character $1,000 Simoleons. Do this as fast as possibly so that you have this command buiding up. Even though your newly created character will say that he has nothing to give, your main character will continue to take the money getting it from nowhere.

Do this as much as you like until you have all the Simoleons you want.