Whaddaya expect when they set out to make a BAD movie, a B-movie, campy horror-disaster instant cult film?

Oh, yeah, and a FUN one. At times. In bite-size doses.

Yeah, the snakes look fake. On-set snake-wrangler or not, nothing bites anybody anywhere in "Snakes on a Plane" that isn't digital or rubber.

Probably a good thing. Because it isn't so much where the snakes are as where they bite you that is the source of the shock laughs in the film from the ex-stunt man who did "Final Destination 2."

David R. Ellis manages to run an efficient shock machine here, with scenes that allow the audience to count down to the moment when the snakes bust loose, shout back at lines that Samuel L. Jackson was born to say (really bad dialogue from several writers) and shriek with delight as this passenger or that one, the deserving and the innocent, take a bite for Hollywood and summer movie glory in places NOBODY wants to be bitten. Ever.

The set-up: Annoying motocross kid (Nathan Phillips, a very bad actor) witnesses a mob murder in Hawai'i. Jackson plays the Fed who protects him as he is escorted to Los Angeles on a red-eye 747 flight.

The mobster has planted snakes in time-release boxes. They get out. And all manner of hissing heck breaks loose, as passengers and crew die by the score in just a few torrid, hysterical minutes, followed by long, dead stretches until more die in a few torrid, hysterical minutes.

They chase, slither up dresses, out of toilets and through air passages. They short out electronics. They REALLY annoy Jackson, who hits his promised "I'm tired of these mutha ... snakes on this mutha ... plane!" line so hard you'd think he was paid by the word. He's laconically heroic, finding tasers, fire extinguishers and the like with which to battle the reptiles.

"It's what I do. I'm very good at it."

Jackson loses no cool points for this one, no matter how cheesy it turns. And that is PRETTY cheesy.

But the truth of the matter is, he's done his best acting over the past month, turning up on chat shows, joking about this junky-and-knows-it movie he agreed to do, just on hearing the title.

Julianna Margulies plays an intrepid flight attendant, heading a cast of "types" — the aloof rapper (Flex Alexander) with entourage, the little boys traveling alone, the new mother, the annoying Brit, the hypochondriac newlywed, the make-out-in-the-lavatory pair, the sissy flight attendant and so on. Their presence must be part of our post "Airport"/"Airplane" DNA by now.

It's not really about the victims, but their mode of death. How cool did they go out? That's the source of the "wheeee" on this summer roller-coaster ride. Sick as it is, it captures more of the joy of movie-going than virtually any other summer movie this year.

But about the fake snakes: Seriously, you can count the real snakes on two hands until the finale, where a separate solid-ground thread of the plot is resolved on a farm with plainly living snakes.

It could never really live up to the hype. But if you're gonna see it, see it in a theater. It simply won't work on the iPod, and it will be just sad to see on DVD. Without a crowd with you, shouting at the screen, applauding at the latest bites, shrieking in mock surprise, you'll be missing more than half the fun. Without the audience, this one bites.