There's a cell with a clear screen called the Pureness. Not only is it crazy expensive but the screen is grayscale and totally useless. That's the kind of tech that needs to be applied to glasses and connected back to the phone over Bluetooth, not used in the primary device.
This picture maybe not as abstract as You think. Icons and elements may be displayed directly on the glas, whole machanism, including touch beams, motherboard, battery may be inside the black part. I don't know if You know one of Sony Ericssons Xperia phones who has transparent screen as well.
I guess transparent are only glasses protecting main screen. Google for image of iPhone without digitizer and check out how does screen without glass look
I actually like some of these mock-ups. More screen real estate and a forward facing camera for video calls would be a welcome addition.
sorry i'm being a deuche.. I haven't got sleep in 4 days and I've been working from 8am - 10pm each day.
its called a transparent oled display. samsung had a laptop at the most recent ces http://www.blogcdn.com/www.engadget.com/media/2010/01/samsung_transp_lap001.jpg the display is real, but afaik theres no touch based screen like this that i know about. so... transparent screen, ok. but transparent capacitive or touch, no