Bring All weapons with you: Go to the start screen and press : Triangle, Triangle, Square, O, R1, O, R2, X, X this cheat will allow you to have ALL weapons on a level.
Dancing Agent 47: On the level "The Murder of Crows" there are three bars - Salsa, Rock and Blues. Once you have acquired the appropriate costume for your bar of choice, go in and stand amongst the dancers and then leave the controller alone. After a few minutes 47 will start to get his groove on with the ladies and start dancing. You can move the camera around to watch him but don't touch the movement control or he will stop.
Extra Mission and Alternate Ending: During the Requiem sequence at the end of the game where Agent 47 is laid to rest, keep tapping up on the left analog stick while the credits are rolling to revive him and play a hidden level. Complete the level and you will be able to view an alternate ending.
