Your Sims can get all the clothes in the game, have some extra money, and move the furniture around and all this in an instant.
These are just a few available cheats all you have to do is install the Cheat Enabler and either in "Create a Sim" or in the game press "Ctrl+Shift+C" to open the console. Now enter "help" to get a full list of available cheats.
Just a little warning: Cheats may have unpredicted effects on your game so use them carefully.