Lytro is developing a so-called light field camera. A camera which uses a special sensor which is able to capture the color, intensity and vector direction of the rays of lights in a scene. Using sophisticated algorithms in software enables many new capabilities not possible with conventional camera’s.
The picture taker and the viewer will be able to change the focus of pictures after they’re snapped or shift their perspective of the scene and even switch seamlessly between 2D and 3D views. You can simulate that by clicking on the pictures in the pages linked above.
It sounds like a really exciting technology and, if it works, can bring a new dimension to photography. However, I have not seen even one picture of a prototype or something that looks like a real product. For now, for me, it’s just a nice story on the internet. I will get more excited if I see a real product which works in real-life.