iFixIt published 2 wallpapers for iPhone that shows us the ‘guts’ of the device, and you can set them as you lockscreen background, or if you are on a jailbroken device, even as you Springboard background.
FSM EXCLUSIVE DEAL To set them as you lockscreen background, save the pics in your camera roll, and set them as wallpaper. Is that simple. If you are on a jailbroken device, and you got a theme ( either a lockscreen theme, or a full theme ) , you will have to tweak the theme via SSH.
Enjoy