Summary: , jump onto the PSP and find the image with the photo browser (remember that you have to click into the Memory Stick folder by pressing the X button too). Find the image you want to use: Now, click on the X button again to have it displayed on the screen, then press the upwards triangle button. Now use the left and right arrows to find Set as Wallpaper : Now press the
Image Dimensions: 532 x 300
Image originally found here.