This is ludicrously cool: researchers at Stanford have developed a camera that lets you focus after you shoot.
It's certainly a research idea at this point: from what I understand, the result is a relatively low-resolution image. But what a disruptive and intriguing idea! You're effectively trading off megapixels against multiple focus depths, which you could select from - or combine digitally - after the shot.
What else could we use all these megapixels for? Could you adjust aperture (and therefore generate different depth-of-field effects) after the shot as well?