A Note and A Tweet

Recently, I posted a letter I wrote to my house. That post was inspired by Shimelle's wonderful journaling class. Here's two other forms of correspondence, inspired by that same prompt.
First, a note I'd like to leave under my daughter's pillow:

If I was on twitter (which I'm not), I would tweet this to my son (who will be getting his driver's permit this week):

It reads: "Dear boy, how can you possible be old enough to drive?"
Are you more likely to write a letter, a note or a tweet?