Designer Senghan Song took the time to render the glass phone.

The phone would essentially be translucent, displaying information and images on a window-like surface in a form factor relatively similar to the iPhone's. The killer feature of this concept phone is its ability to change the look of the display glass to match the current weather conditions of your location (i.e. sunny day equals clear screen, rainy day equals virtual droplets on your screen).
How practical would it be to use a piece of glass for a phone? Possibly good for saving space, and assuming the glass material is harder than normal.

WindowPhone concept points to future of touch cell phones [dvice]