The buttons are very easy to get, assuming there's no long line to get inside. You can also ask CMs, they sometimes have b'day, etc, buttons. And if you're staying onsite (I don't remember) you can tell the CMs at check-in (or earlier) and they can usually help out.
DS has a collection of the honorary citizen buttons. I think mainly they have given them to him b/c he was being cute, but I know that at least one was given when he was crying after having been knocked to the ground in the main bug's land waterplay area by a much bigger kid (preteen vs 3 year old is never going to be pretty). CM appeared out of nowhere with the button and some stickers (we knew the CM was lurking b/c he had booted out some 20-somethings who were messing around endangering the kids).