We've got some nice photos of Samsung's transparent OLEDs, as shown at CES. We don't have any technical details yet. When the screen is off, it is transparent to about 70%-85%. Samsung says these screens can be produced within 2 or 3 years. Here's a nice video showing the same display and offering some more technical details.

Samsung Transparent AMOLEDSamsung Transparent AMOLED Photos from CES 2009Photos from CES 2009
Kyulux - Hyperfluoresence OLED emittersKyulux - Hyperfluoresence OLED emitters