We have had some family fun with "Brain Quest" (you can find them near the workbooks in book stores such as Borders). They remind me a bit of Trivial Pursuit - but the cards are all bound together, making them easier for small hands to hold. You purchase them by age level. I think the oldest is ages 12-13 ... so I'm not sure if that would challenge your 10 year old. But my dd4 really enjoys them - especially if I get cards a few grade levels ahead. The kids can quiz each other or just quiz themselves. These are also good time-killers when waiting for food to arrive at a restaurant.
Have a great trip!
