J.G.
My plan (whenever I becme pregnant with number two) is to put my son in a t-shirt that says "BIG BROTHER" and just see who says something/notices first. (Big brother/sister shirts found at Khol's).
My in-laws live in CA (I'm in Texas) and we do SKYPE often. I will let them see my son on skype video wearing the shirt.
btw - congrats!