Exists since april 15, 2010.
Two goals: supporting Project Gutenberg (by producing e-text) and free e-literature on the web in general ... and more (by linking to 600+ sites that matter, all over the world in many different languages - including general literature, poetry, Greek, Roman and Medieval, Art, Music, Audiobooks, Books and Literature in general, Research, Education and Scientific Publications).
From the Projects page, check out a book you like to work on for a first or second round proofreading. Beginners are fully supported, people wanting to do more will be guided through the whole process - from scanning to pleasantly readable e-book.
(Links will be more ordered thematically and by language in the near future...)