Cheat Mode:
Holding L1, R1, L2 and R2 at the main menu will unlock Cheat Mode.
Decorating:
Holding L1 or L2 and pressing X will speed up the process of
laying wallpaper or tiles.
From the cheat menu, you can enter the following cheats:
MIDAS:
Unlocks all two-player games, all locked objects, and all locked skins.
FREEALL:
Makes all objects cost 0 simoleans
PARTY M:
Ulocks the Party Motel two-player game
SIMS:
Unlocks the Play The Sims Mode without going through the Get a Life
Dream House.