How can I set the iOS Springboard wallpaper to a different image than the lock screen wallpaper without jailbreaking?
After going to the Wallpaper section from within Settings.app and choosing an image;


On the iPad, there are 'Set Lock Screen', 'Set Home Screen', and 'Set Both' buttons on the top of the screen while previewing the image.
On the iPhone, a menu pops up asking whether you'd like it on the Lock Screen or Home Screen, or Both, after tapping 'Set'.