I'm in awe. I can't believe how much better Snakes on a Plane was than I was expecting. I don't even know why. It's some kind of magical mix of gory action and ridiculous hilarity that just clicks. You've got to see it in the theatre... don't wait until it's on DVD, and don't wait until the crowds die down. It's genuinely exciting in a way that I can't compare to any other movie that comes to mind.
Audience participation... Now I can sort of understand the Rocky Horror Picture Show cult phenomenon thing. I haven't seen that movie, but the energy during SoaP was just so weirdly great.
It's not the kind of "so bad it's good" thing I was expecting; I usually just find movies like that intolerably boring. I think it's actually just good in a non-traditional way.
You should go see it.