OK, this isn't really a Web 2.0 application, but it is a very interesting site that is reflective of the massive effort underway on many fronts to digitize books and other writings. In addition to the largest Darwin bibliography and manuscript catalog ever published; through Darwin Online you can access Darwin's complete publications and thousands of handwritten manuscripts, such as 1st editions of Voyage of the Beagle, Zoology, Descent of Man, all editions of Origin of Species, and Darwin’s Autobiography.
Darwin Online is funded by the Arts and Humanities Research Council, and is managed by the
http://darwin-online.org.uk/
http://darwin-online.org.uk/
