I'm involved is a couple of fly-ins, and whenever I try to promote them to the non-aviation public, there is always a big obstacle over the term "fly-in"; why would anyone other than a pilot go to a fly-in? I was surprised over the lack of information I could find on the web. At one time, "air fair" was in common use (and really captures the spirit better, IMNSHO), but some where along the line, the term "fly-in" became the more common term.