Puree melon and berries in blender until completely liquid.
Combine sugar and water in small pot on stove. Heat until sugar dissolved completely in water.
Add sugar water to melon berry puree and blend.
Pour mixture into 13 x 9 glass baking dish. Place on flat surface in freezer.
Every 30 minutes, take fork and scrape the bottom of the dish for approximately 3 hours. 3 hours sounds like a long time but it is easy to do. Let the kids help with this step! This prevents large ice crystals from forming.
When the granita is icy but not frozen hard, take out and scoop into bowls.