Unlimited Money

• Play on any level and complete it, but try to earn as little money as you can. You get docked in pay if you kill too many people, leave your custom weapons lying around, or don't retrieve your suit. Advance through the stats and newspaper screens and save the game. Go on the mission again, and this time get as much money as you can (clean, quiet kills and nothing important left behind). Save the game just before you finish the level. Complete the level, but don't advance to the newspaper screen. Press "Y" on the first stats screen to restart the mission. When the mission starts, load the game you just saved up and exit the level. You will gain the difference in money between your first and second plays each time you do this.
  
  

Unlimited Saves

• While the game is saving, press "Start" to avoid using up one of your saves (not applicable to "Rookie" difficulty level). This has to be done before the saving completes, and it may be advisable to repeatedly press "Start" to ensure that the cheat works.
  
  

Dancing Agent 47

• On the "Murder of Crows" level, go to the one of the three bars when you have found the necessary costume. Stand with the other dancers and don't press anything for a while. Agent 47 will start to dance with the ladies nearby.