Instructions
Press the "PS" button on the controller to power on the PS3 console.
Log in to your user account and wait for the console to load the home screen.
Log in to your PSN account if your PS3 isn't configured to automatically log in by selecting the "PlayStation Network" icon and then selecting "Log in to My Account."
Select the "Network" icon and then select "Internet Browser" from the menu. Press the "X" button to launch the Web browser.
Select the address bar at the top of the browser screen and press the "X" button.
Enter the address for the PS3-optimized YouTube website and then press the "X" button.
Highlight a video to watch and press the "X" button to load it.