Well, I went to a presentation on the service academies with my dad.  I got a copy of a congressional nomination form and it is a big packet with a bunch of questions.  There are parts where they'll ask you about your hobbies and achievements and things like that, and that's where you can probably write dow your HAM radio stuff.  Yes, it probably would be a small plus.  I don't think that there are a whole lot of high school kids out there who do those kinds of things.