I saved a Starbucks coffee cup for the covers because I had originally thought that I would make a coffee cup minibook, but then decided to just cut the cup in half:
On the inside, I used printed photos and ephemera (tickets, brochures, trail map, coffee cup cozy, etc.), as well as pieces from this Christmas tag kit.
I wanted to include the whole Bryce Canyon brochure, but I didn't want to have to take it out of the book rings to be able to open it up. Then I remembered this video I saw on Amy Tan's blog about including tri-fold brochures in a travel journal. I'm pretty happy with the result, though I wouldn't recommend regularly folding and unfolding the brochure.