Writer-director-actor Kevin Smith, who famously tangled last week with ABC-TV critic Joel Siegel after Siegel showily walked out on a screening of Smith's Clerks II, is set to become a film critic himself next week. Smith said on his MySpace.com space Tuesday that he had been invited to substitute for the ailing Roger Ebert on the syndicated Ebert and Roeper movie-review show, where he'll be offering his opinions of the upcoming movies Miami Vice, The Ant Bully, Talladega Nights, Barnyard, and possibly World Trade Center.