The July Issue of Better Homes and Gardens has an article this month in regards to children of the deployed, how to make deployment less stressful, things to do and the like.
One of the things that I liked was something they called a 'Dad Door'. It was a giant cork board attached to the back of the son's bedroom door. It is covered with postcards from Dad, a map of Iraq, pictures, and a calendar that counted down the time left. It also had a shelf built into it so that if the son had ideas of things to talk on the phone to his father about he dropped them into a special bucket, items with which to write letters and other stationery paraphenalia.
Unfortunately BHG apparently does not post all of their articles online, if you were to go out and read it the article is called "Notes from Home" by Linda Vaccariello and starts on page 144.