When I was in Dymocks in the City last week I came across a series called 50 Things. They aren't books they are cards in a box to be used as boredom busters whilst traveling. From memory there were '50 Things To Do In A Car' '50 Things To Do In A Plane' '50 Things To Do On A Journey'.
They are games and activities. The cards can be drawn on with texta then rubbed clean and re-used.
They were in Borders too in Parramatta too so you can probably find them at any largish book shop and if you can't you can always order in
I'll be grabbing 50 Things To Do On A Journey before we go to NZ in August so I'll let you know how well they work in the field after my small team have tested them.