How to deal with toddlers tantrum when travelling by plane.

If toddler ever needed excuses to throw tantrums, they've got them during average holiday; distrupted sleep schedules, erratic eating, long period of enforced sitting, unfamiliar surroundings. Since tantrums in the 'pressured' cabin are even thougher to deal with than tantrums at home, its best to try to prevent them when possible. How to..? Some say few drops of infant panadol will do the trick and some say overtire the baby. What do you say?