Things You'll Need
Instructions
Insert "Portal 2" or another Steam supported game into the PS3.
Press the "Select" button on the game's main menu to open the Steam overlay. If you are not already signed into a PSN account, you will be prompted to do so before you can continue. If you don't have a PSN account, select "Sign up for a PlayStation Network" account and follow the instructions on-screen to complete the registration process.
Enter the email address and password associated with your Steam account using the on-screen keyboard and select "Sign In." If you don't have a Steam account, select "New Account" and follow the instructions on-screen to complete the registration process. After creating the account, you will be signed in automatically.