http://edition.cnn.com/2009/WORLD/europe/07/06/ancient.bible.online/index.html See it online here: http://www.codexsinaiticus.org/en/
It is possible that it is the last surviving copy of the "master" Bibles commissioned by Constatine after the council of Nicea. For those of you familar with manuscript notes in study Bibles this is "B".