Go here: International Trumpet Guild Home Page. The President is my former teacher, and he is a great man helping the organization grow to new heights. I don't know how well it will add to college resumes, seeing as how anyone can join if they pay the dues. However, at an audition, the Professor/Committee will want to know how dedicated you are. By being a member of the ITG in high school, you are telling them that you really love the trumpet and are informed about the greater trumpet playing community. This is huge, and they'll surely like that. It won't make up for a bad audition, but it can only augment a good one.