Hmm anything noisy, but maybe thats not a good idea. Books, small cars, stickle bricks ( small bag), dont know if he would be into tv at that stage? DD wasnt and ds is showing no interest, though he loves music and I put the head phones on him on the way back from our vacation. One thing to remember, bring lots, cos you will be picking up a lot from the floor and its a pain when it rolls under the seats and you dont get it again. Lots of snacks too, the mini cereal packets worked very well for dd. Oh and how about books that make noise? you know what I mean?