I enjoyed the collection Forgotten Bookmarks: A Bookseller's Collection of Odd Things Lost Between the Pages by Michael Popek, but I didn't enjoy it quite as much as I had hoped to. The book is a collection of ad hoc "bookmarks" that Popek, a longtime bookseller (it was his family biz) found in used books his family was reselling. The book is organized into five different sections: Photographs; Letters, Cards, and Correspondence; Notes, Poems, Lists, and Other Written Ephemera; Receipts, Invoices, Advertising, and Other Official Documents; The Old Curiosity Shop: and From Four-Leaf Clovers to Razor Blades. Each page shows a bookmark, the book it came out of, and the bib info for the book.
Some of the bookmarks were interesting--old postcards and torn pages out of personal journals were my favorites--but many of the bookmarks (and the books) just weren't all that fascinating. They literally were just old forgotten items, including some very dull indeed receipts and other "ephemera."
Now, perhaps I am a bit jaded. I was looking for something a bit more exciting. But then, I worked at a public library. My most interesting finds in returned books were (in no particular order): kleenexes (used and unused), bandaids (ditto), cat urine, vomit (and the note explaining what it was so I could be quite sure it was vomit), and yes, once, a $50 bill.* But none of those things would photograph well for a collection like this, I suppose.
*Which I still think we should have got to keep and divide, like booty. I say anyone who has that casual a relationship with $50 bills deserves to lose one once in a while.