One guide had an idea for portable photo printer so we can give a cool photo after the tour.
We are living in a digital, social world. Don't give out photos at the end of the tour. Take their photo and post it on social media tagging your customer and commenting what a great time they had. As long as your customer really did have a great time, and the photo is a good one (get good at taking flattering photos) they are likely to share it. Boom. Free content marketing.