"What really knocks me out is a book that, when you're all done reading it, you wish the author that wrote it was a terrific friend of yours and you could call him up on the phone whenever you felt like it."
You don't need an Official BookCrossing Zone to release books.
I leave books in dozens of places (restaurants, hospitals, coffee shops, food pantries, schools, waiting rooms, Little Free Libraries, laundromats, etc.) , only 3 of which are OBCZs and unfortunately I don't get to them all that often. Don't let the lack of OBCZs stop you from enjoying releasing your books.