This one is curated by university librarians at 530 universities and brings you free full-text access to 2.4 million papers on every conceivable subject.
It's a good place to go for otherwise unpublished doctoral dissertations (many of them book-length).. Some of the papers are undergraduate papers and not that wonderful, but even if you're picky about what you want to read, there's more here than you can read in a lifetime. It ranges from all areas of science through all areas of the humanities. Lots of drivel (especially in the humanities categories) but there are some fascinating gems too.
http://network.bepress.com/
It's a good place to go for otherwise unpublished doctoral dissertations (many of them book-length).. Some of the papers are undergraduate papers and not that wonderful, but even if you're picky about what you want to read, there's more here than you can read in a lifetime. It ranges from all areas of science through all areas of the humanities. Lots of drivel (especially in the humanities categories) but there are some fascinating gems too.
http://network.bepress.com/