Back in the 1960s, there was a popular poster in head shops and hippie boutiques that featured Beat poet Allen Ginsberg wearing a sign that said, "Pot is fun." The stoner comedy "Pineapple Express" seeks mightily to prove Ginsberg right, sending its addled protagonists on a trail of fitfully hilarious misadventures that give new meaning to the term "high jinks."

Seth Rogen, who co-wrote the movie, plays loser Dale Denton, a process-server with a girlfriend who's still in high school and a lifestyle that revolves around two things: getting wasted and staying wasted. When Dale witnesses a brutal crime, he runs straight to his dealer, Saul (James Franco), and soon the two are on the lam from corrupt police, a coldblooded drug kingpin and members of a ruthless Asian gang.

Produced by one-man comedy juggernaut Judd Apatow, "Pineapple Express" joins "Up in Smoke" and the "Harold and Kumar" oeuvre in the annals of pot comedy. What's more, it offers a sly argument for decriminalization of a drug that has become as ubiquitous as those ads for "Weeds." Franco, originally of Apatow's TV show "Freaks and Geeks," delivers a funny, sweet, thoroughly disarming performance as a naive Peter Pan of a dealer who might have been invented by Voltaire. Supporting player Danny R. McBride gives as good as he gets in a sidesplitting fight scene.

By the bloody, hyper-violent finale, though, "Pineapple Express" has gone the way of so many movies this summer: the sadistic Grand Guignol. It's hard to imagine even Mr. Ginsberg seeing the fun in that.

-- Ann Hornaday (Aug. 6, 2008)

Contains pervasive profanity, drug use, sexual references and violence.