This low-budget-looking doc -- executive-produced by ''South Park'''s Trey Parker and Matt Stone -- operates on the idea that watching five physically and mentally disabled adults travel cross-country in an RV and play newscaster for man-on-the-street interviews is intrinsically funny. And you know what? Maybe it is. Even if every encounter doesn't pop, there are laughs aplenty in How's Your News?, as when a lovable lug named Ronnie keeps asking people about his ''spiritual brother,'' ''Medical Center'' star Chad Everett, or a sweet-tempered guy with Down syndrome named Sean neglects yet again to come up with the killer follow-up question. Most astonishingly, this screwball little movie rarely feels exploitative -- and is actually rather moving. Busloads of EXTRAS, including a touching meeting between Ronnie and Everett, and the original pilot, featuring a hilarious interview with random crazy New Yorker ''Hank the Blank, the Motherf -- -ing Skank.''