Who's the Caboose? is a hilarious glimpse of L.A.'s "pilot season," that three-month period when bedazzled actors flock to Lalaland in hopes of getting auditions for new sitcoms. It's a dizzy time of bruised egos, ruthless maneuvering, blossoming celebrity, and every other possible variation on that thematic regular, crazy ambition. Director Sam Seder, who has survived seven such seasons, even getting a role or two, follows aspiring comic Susan (really Sarah Silverman) and her performance-artist boyfriend Max (actually Sam Seder) from New York to Hollywood where they plunge feet first into the froth of wannabe fame. The sleazy agents, stressed-out producers, delirious writers, and duplicitous pals get pasted when they're not already wasted. Giddy auditions and supplementary meets for such riotous pilots as the eponymous "Who's the Caboose?," "Don't Forget Your Mother-in-Law," and the "Untitled Nell Carter Project" are exercises in chortling folly. After seeing Who's the Caboose? you'll realize that it may be pilot season, but there's nobody in the cockpit.-Steve Seid