Here's a simple idea: when you shoot a photo, the camera actually has all of the information it needs to create any shot at all, regardless of "focus." The only reason we focus the lens at all is to create a 2D plane to take the photo. What if you didn't capture just the 2D shot? What if you captured everything? Well, the Lytro is a camera that does just that. If you play with the image on the site, you'll see that you can actually change the point of focus just by double-clicking on the image (compare clicking on the fence with the people in the background).
Apparently, the camera captures depth data as well. The number of applications for this technology is staggering (medical imaging and online product photos for starters). No more worrying about focus when you take your shots - just shoot and pick the idea focus at home. And people thought RAW was neat.