Cheat Gnome:
Press L1, R1, Up, X, R2 during game play.
9,999 Simoleons:
Enable the Cheat Gnome code, then press R1, L1, R2, Right, Left during game play. Select the Cheat Gnome, then Interaction/Location: Give Simoleons.
All lots unlocked:
Enable the Cheat Gnome code, then press Circle, L2, Left, Circle, Up, Circle during game play. Select the Cheat Gnome, then Interaction/Location: Unlock/Unlock All Locations.
Set Skill level:
Enable the Cheat Gnome code, then press Triangle, Circle, Square, R2, Left during game play. Select the Cheat Gnome, then Interaction/Location: Change Skill.
Advance time by 6 hours:
Enable the Cheat Gnome code, then press Circle, Square, L1, Up, Down during game play. Select the Cheat Gnome, then Interaction/Location: Advance 6 Hours.