NEC has been working on flat-panel speakers for some time and is now implementing a tiny one in its newest cell phone for NTT DoCoMo.
The display in the N506iS doubles as the phone's speaker. Users can hear sounds by placing an ear against the screen. The screen on the phone swivels 180 degrees to reveal the keypad underneath. Several features have been added to make the phone easy to use, including the ability to use any number key as the shutter for the built-in camera.
The phone is compatible with DoCoMo's PDC-based network in Japan, so it won't be available elsewhere.
Makes sense... Someone did this in a notebook awhile ago I think -- turned the screen into the speaker. I wonder what the sound quality is like on such a small and rigid screen though...