The Snakes on a Plane teaser trailer is here. Right now, all that's available online is a bootleg copy taped off the movie screen, but if you're a true Snakes on a Plane devotee, it won't matter. The video is pretty hard to discern after the titles, so let me offer what I can make out. It looks like some kind of tube-like creatures attacking a large vehicle of some nature.
Hopefully, they'll also work on the sound effects before release. Right now, these snakes sound a lot like a fat guy holding a video camera, chuckling at the screen.
NOTE: Because of its bootleg origins, there's probably a good chance this will go down.