It looks like your typical hand-lettered store sign but the price is no bargain as the Minnesota Department of Public Safety tries to reduce underage drinking. The poster effort gets away from "the same, boring `We card' message," said Jac Coverdale, creative director at Clarity Coverdale Fury, Minneapolis. The posters are appearing in Minnesota liquor stores. Copywriter: Troy Longie. Art directors: Jac Coverdale, Dave Damman.