(for posterity, this is just copied-and-pasted from my response in the other thread)

Most definitely did so with marijuana. Leaving Vancouver in 2003 with a friend after we had spent a week there. Got on the plane after having smoked for 4 straight hours (in a smoke bar) and having been high all week. I don't even remember packing, but maybe we had packed the night before.

In any case, it was AMAZING, although there were certainly several times when I was convinced that we'd get caught (the inherent pot-paranoia) because I was equally sure that everybody in the airport knew how high we were. It was a relatively short flight...we most definitely stayed baked the whole time, and had a ball talking about utter nonsense.

Not sure if I would've done the same without my friend there, though...if alone, probably just would've smoked enough to get semi-high, just to make the travel a little easier (as much as I fly, I hate it...we've become cattle!).