The kid in the baggy pants on the snowboard has friends - lots of 'em. A survey by the National Ski Areas Association finds that ski resort managers anticipate an increasing number of snowboarders on their slopes in the next five years. Roughly 34 percent of resort visitors are expected to be boarders by 2004, up from 27 percent during the 1998/99 season. Resorts in the Southeast anticipate a far greater percentage of boarders in the future than they had just two years ago, up to 46 percent from 32 percent. Predicts one resort manager in the survey: "Snowboarding teens and young adults will move into the workforce and create an older, more affluent snowboarder market."