IMO a small magnadoodle is one of the best travel toys EVER
I second pipe cleaners & beads. Pieces of cut lanyard and beads are good too. My girls even like those basic twistie ties. Every time we're in the supermarket, they grab handful in the produce aisle and enterain themselves for the rest of the shopping trip and then some.
Does he have a leapster or ds?
I've seen a magnetic tangram set that some kids enjoy.
Yes, rush hour or rush hour jr is great. just a warning that the rush hour Jr is too easy for some kids, so you may want to test it out before you bring it along.
Small games like jax or chalk for sidewalk games like hop scotch. If he's into imaginary play, a small set of play animals may be fun. I know some kids can spend lots of time with those. Throw in a small tub of playdoh and the animals can leave footprints where they walk or ds can make them landscape, accessories, whatever.
My dd doesn't like coloring much, but she will cut and paste for hours coloring the pieces she cuts, so maybe pack a small pair of kids scissors and some glue sticks. You can buy paper or carstock there so you don't have to lug a bunch over.
Klutz makes a line of books for the younger kids called Chicken Socks. I'll bet you can find one that suits your ds's interests. Dd has one with different colored rolls of skinny tape that you cut to size and use to decorate the pages of the book, some pages are pre-printed with designs and pictures and some pages without. Again, the cutting & sticking is lots of fun.
what about a sticker atlas? Usborne makes one. He'll be in another country so perhaps he'd enjoy learning more about geography.
