At the last minute I picked up 2 items that will become part of my requirements for all future trips - a compass and a flashlight.
I purchased a small round compass with a clip/pen to attach to you or your belongings. I attached the compass onto the strap of my daypack so all I had to do was look down on my shoulder and see which direction I was heading. Although I'm pretty good with reading maps, it's confusing when you're walking deep in the heart of a medieval section of a city or driving through a poorly marked town trying to find your hotel.
I also bought an ultra-light, very small but strong flashlight. This was great for peering into the corners of dimly lit churches, getting a good look at where you're walking in the rain at night on wet cobblestones, and even looking inside a Moorish vase!