I like this as a way of displaying family pictures too! If you still wanted to do the traditional family tree, you could always use this idea for displaying pictures taken in the classroom and pictures with friends - their "classroom family"
Take a picture of each child holding a sight word. Then make a power point presentation with those pictures of each child holding the words, and use to practice sight words. Email the powerpoint to the parents so they can use it to practice at home
Create an interactive display for use in your classroom. Perfect for schools that teach through the RWI phonics scheme. Buy a 'KROKIG' wall storage unit from IKEA (currently and add these eyes to make a frog. This could be used to sort sounds -