I totally agree about letting your child know they are different. I was never ID'ed GT in school, but I always felt different and I seriously thought something was wrong with me through elementary school. It would have been extremely empowering to know "why" I felt different and that there were other people who felt the same.

DS knows he is GT, but I've always told him that just makes it easier for him to learn certain things. Some people take a little longer. He's more likely to call himself dumb, than brag about how smart he is. Which is annoying too. Occassionally, he'll throw out his reading level (his teacher told him this) if someone comments on some book he's carrying around.