Instructions
Turn on your PS3 and access the main menu. Make sure there isn't a game disc in the drive or else the PS3 will direct you straight to the main menu of the video game.
Select "Game Settings" from the main menu screen after it has finished loading.
Scroll down through the list of options, all the way to the bottom, and select the "Network Settings" option. It should be the very last option in the list.
Select "Settings and Connection Status List." It should be the very first option in the window. Wait for the "Settings and Connection Status List" window to pop up.
Scroll down through the list of settings and connection information until you get to the bottom of the page. Here you will find a 12-digit alphanumeric number listed under "MAC Address." This is the MAC address of your PS3.