I have flown with my kids quite a bit over the years and have a few suggestions of my own plus some I've seen on this site before. First, try to have some "new" toys that he hasn't seen before that will keep his attention. Other moms have wrapped these in wrapping paper like a present. Having the child have his own backpack/carry-on with these items and at least one change of clothes will be helpful. Yes to the lollipop and/or sippy cup. Also having many different snacks will be helpful. I also agree with letting your son run as much as possible before getting on the flight. I really like the idea of the car organizer, too! What I would do was to take along those plastic chain links - I attached them to the toys, sippy cup, etc. This way you aren't trying to locate dropped stuff on the floor of the airplane (hard to pick up,plus the germs!!!ick) We have also taken a laptop with DVD's for the kids, but since your son is 1, he may not watch them for any length of time. Now, I know giving kids Benadryl is controversial. I always had it with me if I felt I needed it. Sometimes, even if a child is really tired, the strange environment will prevent them from falling asleep. I chose Benadryl over any sort of cold medicine. Plus, make sure you have some children's MOtrin/Tylenol, Vix vapo rub, thermometer, etc. in case your son would happen to get a cold or such - even while you are in Puerto Rico. This way you have it and won't have to go looking for it if you need it in the middle of the night (or middle of the flight). Lastly, like other comments, trying to relax is key. Usually, the anticipation is worse than the actual flight. Try to enjoy yourself and good luck!