Kind of interesting:

Treasures hiding in plain sight
A collaborative Widener Library program rescues vulnerable books

I especially liked this because a) I love finding random stuff in books; b) I love stumbing across random books; and c) one time my brother found a book in Widener which, apparently, had had the first page illuminated by the author. Awesome!

The downstairs (used and remainders) section of the Harvard Bookstore, across the street from Widnener, also has a collection of the random ephemera they've discovered in the pages of used books they've purchased for re-sale, which I find endlessly entertaining...