Don't mean to be a buzz kill but doesn't this already happen? I mean whenever a big show comes around my area, like Hot August Nights in Reno, every bird owner I know tries to get together so we can have a meet and greet. I know there's a good sized show near So Cal, Route 66 show I think. I'd be willing to bet everyone down there does the same. It is an awesome idea for one national gtg but I don't think it's practical for most people. I'll be there after the divorce(meant to be sarcastic, you'd have to know my wife).
