CHEATS   

Sly 3: Honor Among Thieves

Alternate Plane
In the third episode, when Sly is flying the biplane, press Start to pause the game.
Press R1, R1, Right, Down, Down, Right.
After resuming the game, Sly's plane should look different.

Secret Combination Codes
In Guard Duty, you need three sets of blueprints.
Those are stashed inside combo safes, hidden behind rare art paintings in each coffee house.
Somewhere in the painting there's a secret combination code hidden in the background.
Use these 3 codes for the painting in each coffee house.
Painting 1: 4 - 7 - 9
Painting 2: 9 - 6 - 8
Painting 3: 1 - 1 - 3