Instructions
Insert your "Uncharted 2" game disc into your console. If your PlayStation 3 does not automatically load the game, select the "Uncharted 2" icon from the "Game" menu with your controller.
Press "Start" at the main menu to reveal a list of options.
Select "Multiplayer." Your copy of "Uncharted 2" will verify that you are logged into the PlayStation Network, which should happen automatically every time you turn on your console. If you are not logged in, you will be prompted to do so.
Enter your user name and password and select "Sign In." Once this has been verified, "Uncharted 2" will sync all the live data with your console and load the multiplayer options on screen.