I've been having good luck vaping at the movie theaters near me.
During "Hunger Games" on the opening night in a packed theater, I only got noticed when I got a bit careless and let out a big plume of smoke without a double inhale. Even that wasn't that bad, I was just embarassed when a woman behind me said "What?!? Is he smoking something?!?", after which point I was more discreet.
This past week, I went to see "21 Jump Street" with my nephew, and specifically inquired of the person at the counter what the AMC policy on e-cigs was.
He asked his manager then stated "We don't have any official policy, but they aren't allowed [pe se. If someone gets upset, we'll kick you out".
Pretty good experience, and the movie wasn't, honestly, as terrible as I'd expected, which was an added bonus.