Bring sugar and water to boiling and cook till sugar dissolves. Stir in chocolate. Set aside and let cool.
Stir well and pour into freezable dish. I used a 11x13 glass baking pan.
Stir in juices and fruit. Mix well.
Remove from freezer about a half hour before serving so it can soften to a slushy consistency.
Serve into glasses. Garnish with mint leaves. Pour lemon-lime soda over (if using) and serve.