Finally. . . a journal, and some pens

Bringing a book in which you can keep some sort of journal is a must. I guarantee you that you will be very glad you did after your trip, because the memories do fade. Use a journal not just for recording memories of your trip, but for recording good advice you get from other travelers, phone numbers, addresses, and so on. You should probably leave your address book at home, and take all the addresses you need in one of these. A small bound book will outlast a notebook by centuries, and may even end up amusing your grandchildren. Bound blank volumes are available at any office supply store or college bookstore.