Claudio Soares, a Brazilian novelist and the organizer of a blog on Joaquim Machado de Assis, a 19C Brazilian pre-Nabokov, has drawn my attention to this article on Pontlolit, an online magazine he edits;
http://www.pontolit.com.br/blog/2008/11/08/bibliographic-collaboration-via-librarything/
It would be wonderful to have VN's and VDN's libraries available online. We did try to start a related project, on What Nabokov Read, which Michael Juliar invested a considerable amount of time on developing software for several years ago, only for the project to come to nothing. (Perhaps someone needs to do THAT prject as a book.) VN's own library, after he left Russia, was never large; most of the books he had read he stored only in his head. VDN's library does have two printed catalogues, 1904 and 1911 and he would undoubtedly have kept acquiring books until 1917.
Cheers,
Brian Boyd