We just got back from Hawaii with our 5-year-old who has been an excellent flier. On the outbound flight, we took DVDS and activity books along with something new that a friend of mine had suggested we buy him for when he started getting restless. That worked beautifully. I prepared him from the beginning about how we would "spend the night" and sleep on the plane on the way back, so that was fairly easy--it took him awhile to go to sleep, but he slept on the way back. He had no trouble adjusting to Hawaii time--he had a nap on the airplane, so I kept him up until bedtime Hawaii time the very first night and I think that helped. Plus, we pretty much stayed on the same schedule as him. We went to bed with him and woke up with him so we were all rested and on the same page. We arrived back home on Thursday morning and we are all still struggling to get back on our schedule. Tomorrow will be interesting! I'd say make sure you take and use a lot of sunscreen--that sun is awesome but very strong there. I kept reapplying it to my son and he never got burned--the waterproof, sweatproof spray in 70spf was awesome and easy to use. I did use a cream on his face AND SCALP as well. He also sometimes wore caps, sunhats and sunglasses during the hottest times of day. Also, the swimsuits and swimshirts (rash guards) with SPF (even Gymboree sells them) are wonderful--they truly protected his skin and dried superfast. You might want eye drops--by son kept rubbing his eyes so I don't know if it was salt water, suncreen or sand, but that came in handy. A shovel, bucket and other sand toys, along with an inflatable life jacket kept my little guy occupied for hours. You might be surprised how much your little one enjoys that too--the sandy areas were full of toddlers and little ones loving the sand and water. We had a great time and hope that you have fun too! By the way, in response to the car seat suggestion. I have to tell you, with all you have to carry with you, I'd leave the car seat at home. We never traveled with one even when he was a baby (you might check airline requirements). We just rented them for a small fee with our rent car and it was worth every dollar. It is much eaier than dealing with another item to carry and put through security. You will have your hands full already. Also, we left our strollers home too and went to nearest Walmart and purchased a cheap umbrella stroller for less than $15 that we just left behind. Again, worth every dollar not to have to deal with it. I'm sure many would disagree, but we like to travel light and avoid shoulder and back pain. All our vacations and trips with our son have been so easy due to this philosophy!