As a very young folkie (high school) I would say that one reason so few young people are involved in the folk world is a total lack of exposure. While there are a number of teens into folk, it's usually because they were brought up with the music. Folk doesn't need to be made "more appealing" to kids, because a lot of the time, when they hear folk they like it. A lot of teens go in for filk- sick sense of humor is truly appealing. Also, some of the faster paced Irish, Cajun, Acadien or Scottish stuff is liked. Generally, kids who like aoustic and have enough free time will find the internet and stumble into the wide world of folk. A lot of aspiring guitarists start getting into blues and folk. However, it tends to be the "weirdos" who go in for this kind of thing. So really, my advice for attracting younger people would be to just avoid creating a "no kids" atmosphere. Really, having a sense of humor about things helps.