If you’ve taken the time to download the iPhone SDK, open up the Aspen Simulator and go to the home screen. Now, go to Hardware menu and chose Lock. SpringBoard (the home screen icons) explode outward to reveal the lock screen.
You got a hint of this effect if you have a Jailbroken iPhone, as the springboard sorta locks up after a new application is installed.
This is a neat effect I didn’t know SpringBoard had. It had to be something tested internally, since locking the screen on a production device… turns the screen off, thus masking the effect. I suspect that this effect would load up if the user were to have an application installed remotely (say, in iPhone 2.0).
Also, a little bug, when you do lock the screen manually, the flashlight effect over “Slide to Unlock” doesn’t appear.