High School Radio Stations - the future?

Sunday, 11pm GMT, 7pm EST What is the difference between a webcast and a radio station for a high school? Is there a need/value for a high school radio station in this day of so much "media" everywhere we turn? At our NYC public high school, we've experimented with webcasting author visits and a few student run sports shows. When and where should they be happening and if one of the greatest aspects of our newest technologies is the ability to share, how can we be sharing these events with other schools and finding their experiments for our students to explore?