Wondering how far megapixel imaging can go? This page from David Bergman explains how he took an almost 1,500-megapixel image at the presidential inauguration. He used a robotic camera called a Gigapan taking a series of still images that were then stitched together (image stitching of video surveillance is available from companies like DVTel in its SceneTracker system, as well as some other companies in our industry). The amount of detail you can get on the crowd is simply unreal. Use the scroll controls to zoom in anywhere and check out the detail. Obviously this isn't realistic for video surveillance, but it's a nice glimpse into what could be the future.