Yesterday I placed a letterbox in our high school's library. The
students had to answer 5 questions, take a specific part of each
answer and then find the book that went with that call number. Cut
into the book was a nice little hole for the stamp. The book was
donated by the librarian (which, in their sense of humor working
overtime, was about the history of the printed book). I gave this
assignment for extra credit, but the response has been interesting.
Those that understood the process were so excited to find the stamp
that they practically ran to my room after they stamped in! When
some of these students gave me the results (the answer sheet had to
have the stamp on it), those who did not originally get the idea or
had no motivation to do it became very curious and motivated.
Overall the experience has been a lot of fun, heck my seniors were
trying to do it!

J. Peter