Since Kim asked:
Basically, there's this horror/disaster movie called "snakes on a plane" starring Samuel L. Jackson. It is supposed to be somewhat campy and is a huge joke on the internet. I went to see it because I thought it would be funny, but actually it freaked me out. It's not for the squeamish. The snakes tend to bite people in really uncomfortable places.
For people who like disaster movies or you more grossout kinds of horror movies, that's great. For me, who was expecting something a little less gross and a little funnier, it wasn't so great.
Without spoiling anything, I can say that the plane, which is a regular commercial flight, is transporting an FBI witness against a mobster from Hawaii to LA. The mobster arranges to have 500 poisonous snakes put on the plane in a time-release crate that lets them out when they are over the ocean.
Here's the wikipedia article if you'd like more information, though that has spoilers, so read carefully if you want to avoid them.