David Bergman, has an amazing portfolio, wich includes rockstars, presidents and lots of important events like the Barrack Obama ceremony, where he did a 1474 (yes! that’s right!) 1474 megapixels picture! he explains everything here but basically he used a technology called Gigapan, and 220 Canon G10 images and the file is 59,783 X 24,658 pixels and 2 gigabite size.
you can spend a while searching for every single detail in the pictures below :)
The CNN also did something with people’s pictures of this ceremony using a technology called Photosynth from microsoft they are putting together a 3-D model of that moment, pretty interesting also. Check it here.