For a "layman's explanation" of the physics, I found Phil Plait's article about the iPhone 4 (http://blogs.discovermagazine.com/badastronomy/2010/06/10/resolvin

For a "layman's explanation" of the physics, I found Phil Plait's article about the iPhone 4 (http://blogs.discovermagazine.com/badastronomy/2010/06/10/resolving-the-iphone-resolution/ http://blogs.discovermagazine.com/badastronomy/2010/06/10/re...) really instructive. See "1) What is 'resolution', really?"