And, of course, the biggest free souvenir of all: your photos. Last summer, when I was traveling with a friend in Norway, her phone got stolen, and she lost all of the pictures she had taken on the trip so far. For this very reason (or, say, dropping your phone/camera in a river/toilet/off a cliff/etc) it’s important to back-up your photos on a cloud. Try to do it every night while traveling if you can. Personally, I use Dropbox, but there are many cloud storage options out there.