I haven't seen a PSP psd template - might as well be the first, eh?
I included a flames layer...booyah!
Please, please, please - if you use this, send some love by way of credit in your deviation.
Make your kick-ass psp wallpaper the appropriate size and compress it into a .zip or 7z (or some other compressed type).
Open the psp psd template.
drag your wall into the labeled layer, nudge it into position and save as a .jpg.
Submit your zip file (the wallpaper only) and use this template-ized version as the preview.