Mildly funny adventures in extreme baby-sitting, director David Gordon Green's "The Sitter" finds its emblematic moment in the scene of Sam Rockwell, playing a Brooklyn drug dealer, joking around and then suddenly blasting one of his minions in the foot in a realistically painful way. That's Green for you. He's the man behind "Pineapple Express." Hahahahaha and suddenly there's blood on the floor.

If it were up to Green, every movie would ride on the careening mood swings of a '70s picture such as "Freebie and the Bean." He's an interesting director of considerable talent — he made the beautiful, patient dramas "George Washington" and "Snow Angels" — so even when he's just delivering an 82-minute star vehicle, fast, cheap and on a modest budget, at least there are things to discuss. And at least "The Sitter" is built around Jonah Hill, who has what it takes to anchor a stupid, crude comedy. Unlike Danny McBride, who served as the nominal center of Green's stupider, cruder "Your Highness."

The brisk first scene in "The Sitter" establishes a great deal in just a couple of minutes, introducing Noah (Hill) with his sometime/not really girlfriend (Ari Graynor), whose interest in cocaine sends Noah on a dangerous, all-night mission with three kids in tow. The eldest (played by Max Records of "Where the Wild Things Are") is an anxiety-riddled wet blanket; the adopted El Salvadoran middle child (Kevin Hernandez) is a pyromaniac who likes to blow up toilets; the youngest (Landry Bender) is a female preteen dangerously into looking like a trashed-out celebrity en route to the Betty Ford Clinic.

These kids and their overbearing insecurities need Noah's tough love, according to the slapdash script by newbies Brian Gatewood and Alessandro Tanaka, and if "The Sitter" finds an audience, it'll be thanks to the movie's collision of nastiness and sentimentality. That's how a lot of comedies are these days, some more amusing than "The Sitter," some less. I hope Green one day finds a way to bridge the style and rhythm of his early pictures (the ones that didn't make money) and the bumper-car approach of "The Sitter."

'The Sitter' -- 2 stars

MPAA rating: R (for crude and sexual content, pervasive language, drug material and some violence)

Running time: 1:22

Opens: Friday