purple Sharpie marker. She was pretty sad before I left for my last work trip, and I read somewhere in blog-world about someone doing something similar for their child that was missing them during the day.
I drew the hearts so she had a visual reminder that I was thinking of her, and carrying her with me all the way to Canada. The hearts faded, but Bo was great and re-drew her heart for her each day until I came home. The picture of her little wrist with the heart is my iPhone wallpaper right now.
It was a simple gesture, but she seemed to like the idea and it may become one of those family traditions. (And, when she's an adult and gets a heart tattooed on her wrist, I'll have only myself to blame. LOL!)