Bald, with gaping eyes and a hippie fringe that frames his puffy cherubic face, Josh Kornbluth is the most combustible of comic nerds; he looks like a gentle, overweight blowfish who's about to explode. In Haiku Tunnel, the flip, intermittently hilarious office comedy he cowrote, codirected, and stars in, Kornbluth plays a San Francisco temp secretary who's a loafer, a liar, and a passive-aggressive ''creative'' drudge. He's the ultimate overqualified underachiever. By now, countless corporate farces have fetishized the fluorescent tedium of life as a glorified copy-machine slave, but Kornbluth adds an amusing pathological element: His character is so devoted to avoiding anything that resembles actual work that he's more meticulous about screwing up each task assigned to him than most people would be performing it. (The job of transcribing and mailing 17 of his boss' letters becomes a campaign worthy of Napoleon.) Adapted from a stage monologue, the movie treads a tightrope between the witty and the cartoonish, but Kornbluth, with his softly discombobulated rage, makes you want to see more of him.