Much like salton10 said, I've had many people ask me "What is his nationality?", and I'll say "He was born in Guatemala", and this usually ends up to a conversation about their bothers' best friends sisters best freind is also adoption from Guatemala. I think its a great conversation started. Of course, someone asked me this at the hospital one day and I answered "Guatemala", and she called her friend over and said, "Check out this cute little boy! I thought for sure he was Cuban like my husband, but his daddy is Guatemalan." She never even got that he was adopted!
I was also approached at a store my a women who came up to Alex because he was smiling at her and said "What a beautiful baby! I have 2 twin girls at home that have the same beautiful skin. They are adopted from (I can't remember where)." She outed herself and we had a great conversation! So a compliment on a cute Alex is always works for me.