NASA has released a new Blue Marble image, showing the United States of America. According to them, it's the "most amazing, highest resolution image of Earth ever." Blue Marble 2012 bests the 2010 edition and the original one.
The original one—the default background image in the iPhone—was 2048 x 2048 and was made combining different images. The 2010 edition was created with data from NASA's Terra satellite. But Blue Marble 2012 uses the latest data from NASA's newest Earth-observing satellite: Suomi NPP. It's made from several passes taken on January 4, 2012 using the satellite's Visible Infrared Imager Radiometer Suite instrument (VIIRS).
You can download it at a whooping 8000 x 8000 pixels. The detail at that resolution is amazing, but I recommend 1024 x 1024 for all your tablet, phone and computer background needs. [NASA Goddard Flickr]