I dropped my iPhone 3GS this week. It fell perfectly face down on the pavement, and the glass front shattered.
The screen still works perfectly, and so does the touch-screen. Unfortunately some of the shards of glass are loose and they have an unpleasant tendency to stick in your thumb when you swipe to unlock the phone.
I will almost certainly have to pay for the repair out of my own pocket – and maybe even buy a whole new handset. Currently all of the iPhone handsets retail for over £400.