2.5 billion pixels
This is an article about some people in the Netherlands who made the first gigapixel panoramic photograph. you can zoom way in on the website, its quite astounding.
The finished image is 2.5 billion pixels in size - making it about 500 times the resolution of images produced by good consumer digital cameras.
The huge image of Delft was created by stitching together 600 single snaps of the Dutch city taken at a fixed spot.
If printed out in standard 300 dots per inch resolution, the picture would be 2.5m high and 6m long.
i'd love to do one a macro version of one of these of something like a rotting pig carcass.