Interesting that this thread has been bumped. My husband just encountered this on an AA flight from MIA-SFO. Someone in the exit row pulled one of these out and my husband said it looked and smelled just like someone was smoking a real cig. My husband mentioned it to the flight attendant and the FA ended up confronting the guy in the exit row. After some heated debate, the FA managed to convince the guy that AA had a policy against the use of these devices.

Do they really smell like real cigs? If they are even close I suppose I would prefer that people didn't use them in flight.