Disciplining a child when traveling

Something I struggle with regularly when we travel is how to effectively discipline B when we are traveling.  If he has a tantrum at home or in the car, we can just let him scream away in a safe spot or in his car seat while we ignore the meltdown.  But this isn’t really an option on a flight, on a bus, or in a hotel room.  And despite knowing I am doing the wrong thing, I often find myself being a bit more lax on naughty behavior simply to avoid some of the toddler squabbles.  I'd love to hear from readers on your own experiences and thoughts on the topic!