totally turing off the screen?

hey fellas

i cant find it anywhere but i was wondering whether i can totally turn off the backlight or the whole screen so it goes black n u cannot see nething

i know that there is the button at the front that u hold for a few seconds but i want the backlight to stay off when i press buttons.  this is becuase i use the mp3 function and i want to get as much battery power as possible also i dont want the screen getting ghosted.  when i turn off the screen from that button, i change a track n the screen comes back on

thx

Theres only one way to do that...

-Buy a PSP Remote & Earphones

-Plug it in

-Select a song

-Turn the screen off

-Put the PSP in lock mode

You can change songs with the remote and the screen wont turn back on.