I don't want to know what I spend on books. I do frequently seem to find take-a-book, leave-a-book places on my travels (I've found these everywhere from B&Bs in Indonesia to a Fairmont in the states), and I've read some interesting books that I otherwise wouldn't have as a result. Cruisers - as in those who sail fulltime - make it a habit to exchange books with other cruisers at every anchorage. I wouldn't travel with library books only because I like to leave reading material behind as I go and free up space.