Quoting from the Website of Codex Sinaiticus:
Codex Sinaiticus is one of the most important books in the world. Handwritten well over 1600 years ago, the manuscript contains the Christian Bible in Greek, including the oldest complete copy of the New Testament. Its heavily corrected text is of outstanding importance for the history of the Bible and the manuscript – the oldest substantial book to survive Antiquity – is of supreme importance for the history of the book. [Find out more about Codex Sinaiticus.]In the current project they will be reuniting the entire manuscript in digital form and making it accessible to a global audience for the first time. From 6 July 2009, the Codex Sinaiticus website features all extant pages of the Codex.
For years I have heard about the existence of these manuscripts and I view this digitization as a major contribution to Biblical scholarship.