Our favorite: a box with a (barely recognizable) image of a lion, a slot for a mouth. "Gentlemen are requested To deposite in the Lion's Mouth the TITLES of such BOOKS As they may wish to have IMPORTED", it reads. (We do it with a blue postcard, in exactly the same spirit. You ask for it, we get it.)
We have a couple of very nice books about the history of libraries. Matthew Battles' Library : an unquiet history is extremely readable. He has some material on the early history of libraries in the US. Though Luciano Canfora's The vanished library, about Alexandria, is not nearly so smooth, if you love libraries you may always have wanted to learn more about the library at Alexandria; this book will satisfy that wish. The book on the bookshelf by Henry Petroski is not explicitly focused on the history of libraries, but sure has a lot to say on the subject.