Here is a little pack I made awhile ago. When you convert your PSX games to EBOOT files in order to play them on PSP, they don't need to look ungly in the XMB screen. Just add those two pictures during conversion process (changing the title in the icon and adding appropriate picture to the background) and voila Hope it comes in handy.
The zip file contains both icon and background's PSD files.
The PlayStation and Playstation logo are copyrighted by Sony. All rights reserved.