Light field camera

The eye and conventional camera's capture the colour and intensity of light. They need to focus to get a sharp image for a certain distance.

Light field camera's also capture the direction of the light rays.
This allows you to reprocess and refocus the light information afterwards.
Storing this extra information takes up about 200 times the space of a classical picture. So the camera's have to sacrifice resolution to keep picture storage size within limits.
Lytro will bring a consumer light field camera to the market next year.  An 8GB version costs $400 and stores 350 pictures.

You can refocus some pictures in a demo at their site.