Things You'll Need
Instructions
Open the PlayStation Network and select the "Sign In" button.
Go to the "Friends" column on the far right of the PS3 main menu and select the "Players Met" panel. Your PS3 will list all the players you have played online games with.
Select the name of the person you wish to find. If the player is not already in your Friends list, the "Add a Friend" request box will come up.
Select the text box to bring up an on-screen keyboard, and type the message you want to send. Press "Start" when you're finished entering your message, then select "Send."
Look in the "Friends" column to see if the person you sent the message to accepted your friend request. If he did accept, he will be listed there every time you turn on your PS3.