Cheat Gnome:
Press L, R, Up, A, Z during game play.
9,999 Simoleons:
Enable the Cheat Gnome code, then press R, L, Z, Right, Left during game play. Select the Cheat Gnome, then Interaction/Location: Give Simoleons.
All lots unlocked:
Enable the Cheat Gnome code, then press X, B, Left, X, Up, X during game play. Select the Cheat Gnome, then Interaction/Location: Unlock/Unlock All Locations.
Set Skill level:
Enable the Cheat Gnome code, then press Y, X, B, Z, 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 X, B, L, Up, Down during game play. Select the Cheat Gnome, then Interaction/Location: Advance 6 Hours.