You will need two PSPs and two copies of the game for the first trick. Select the item you want to duplicate and trade it to another PSP. Don't save on your PSP but save on the other one. When you reload, because you did not save, you will still have the item. However, since the other PSP saved with the item on it, they will also have the item. Alternately, connect to a multi-player game and have the character with the item give it to another player. Do not save the game when exiting. The player who receives the items must save the game. When both players reload the game, they will both have the item.