Just my $0.02:
DO NOT vape ON A PLANE. While you can easily get away with it, and plenty of people do it...the chances of causing a scene and ruining it for all of us are quite high, especially if you are on an international flight.
That being said, there are good tips in this thread on how to get away with it, if you absolutely cannot survive a flight w/o vaping.
It is kind of a common sense thing but unfortunately common sense is not something everyone has. No matter how well most of us stealth vape there will always be some ..... making a scene etc. Me not stealth vaping on a flight isn't going to stop the .......