Just got back with my 17 month old son. He really shocked us on the plane. He was so good. we did take his carseat and I think that helped a lot. He just sat in it and watched DVD's for almost the whole time. My son loves TV though. He also took a short nap on my lap.

Be careful with the sleep aids. They can have the opposite effect sometimes and get them wired. Try at home first if you plan on using. We just gave him some Motrin before the flight in case his ears bothered him and he was fine.