A tip for filmmakers attempting to appeal to young moviegoers: Don't hire thirtysomething actors to play recent high-school graduates. Or, more to the point, don't hire Vince Vieluf, who, as the most out-there of the four skateboarding buddies at the center of Grind, edges out Northfork's Anthony Edwards as this year's second-for-second most annoying supporting performer. Loud, grabby, and dirty, Vieluf seems about as human as the zombies from 28 Days Later, though he lacks an interest in eating flesh. It doesn't help that he plays a character obsessed with farts and poo in a film where most characters merely have a passionate interest. Take bland, fresh-scrubbed protagonist Mike Vogel: Though he works at ground zero for excretory calamitiesa suburban Chicago fast-food restaurant called Chili 'N' Suchhe still has enough outside interests to hit the road after graduating from high school, following pro skater Jason London in hopes of finding his own way into the professional circuit. Quickly enlisting the eager, gaseous Vieluf with the promise of adventure and girls, Vogel rounds out his posse of likeminded Thrasher subscribers with the help of college-bound best friend Adam Brody and ladies' man Joey Kern, whose character and performance have been lifted wholesale from Matthew McConaughey's role in Dazed And Confused. But it doesn't take long for the boys' plan to hit some less-than-gnarly snags, including a lack of funds, cameos from a wig-clad Tom Green and others, and a rival team whose pale skin doesn't stop them from spouting hip-hop lingo with abandon. Nevertheless, by film's end, Vogel and company learn that there's no problem so great that an impromptu breakdance routine to "Bust A Move" or a singalong to Poison's "Nothin' But A Good Time" can't solve. (The soundtrack seems to have been tailored to the age of the filmmakers, not their characters.) Between fart jokes and leering footage of female skate fans, first-time director Casey La Scala and some talented stunt doubles squeeze in a fair amount of impressive skating footage, but the film around it will gleam the cube only of viewers with an unusually high tolerance for porta-toilet and Dutch-oven gags.