An alternative to buying a Passport is to make a mask at the Kidcot stations. At the first country you go to, ask for a mask - it will be mounted on a stick you hold on to and have cutouts for eyes, etc. A dangly earring is attached at that first country, and at each subsequent country they hang another one on - they each have some connection to the country. Kids can decorate the mask w/ crayons and markers and generally turn them into a "work of art". My 9 yo DS enjoyed this!
Another suggestion is to have your child's autograph book signed by the person working Kidcot. They typically write a sentence or so in their language and sign it, which is pretty interesting - especially from a country that doesn't use "typical" english characters. We found the CM's working Kidcot to be VERY GOOD with children, sharing info about their country.
Have fun!