What is it all about?
OLED (Organic Light Emitting Diodes) is a flat display technology, made by placing a series of organic thin films between two conductors. When electrical current is applied, a bright light is emitted.

Because OLEDs produce (emit) light they do not require a backlight. This means that OLEDs can be made very thin and very power efficient when compared to LCD (which do require a white backlight). OLEDs can be used to create white-light, too.

So what does it mean to me?
OLEDs have the following advantages over todays flat-panel tech (LCD or plasma):

Low power consumption - OLEDs are a far better choice for portable devices. It also makes OLEDs much more environmental friendly, and a candidate to be the white-light bulb of the future
Faster refresh rate and better contrast.
Greater brightness - The screens are brighter, and have a fuller viewing angle.
Exciting displays - new types of displays, that we do not have today, like ultra-thin, flexible or transparent displays.
Better durability - OLEDs are very durable and can operate in a broader temperature range
Lighter weight - the screen can be made very thin, and can even be printed on flexible surfaces.