I don't fly much, but I just flew to Denver and back last weekend, and didn't try to vape on flights either way (one was SW). They were short enough and I didn't feel the urge. However, I was stuck in O'Hare for 4+ hours on the way back due to weather delays. I was too chicken to ask security or anyone that works there if vaping was allowed in common spaces, so I did the toilet vape a couple of times. The second time I must have been next to the REAL breakfast burrito guy. Blech! Anyone know the rules in airports, or is it on a case by case basis?