Glad I found this thread, because I'm thinking of switching to e-cigs myself.
I'm also stressing about a long-haul flight I'm due to make in June (13 hours plus) and how I'll get by without my nicotine fix. I've managed shorter flights with nicotine patches and/or other other NRT products, but nothing as long as this proposed flight.
I've read varying reports about the use of e-cigs in flight, from airlines allowing pax to use them openly in the cabin to those who specifically ban their use altogether, with all sorts of variations in between. Some pax have stated they have used them in the lavatories, with or without the permission of the cabin crew.
No-one has mentioned having an issue passing security and carrying them onboard, nor having set off any smoke alarms by using them in the WC.
It would be a great weight off my mind if I knew I could enjoy a discreet e-smoke or two during a long-haul flight, and I'm torn between following the advice of the many e-smokers who say just do it anyway, and the very few posts (from people who may or not be airline staff) who state it's an absolute no-no.
It makes total sense to ask my carrier, of course (likely to be Qantas or Emirates) but I'm not expecting to get the answer I want to hear!