Scandinavian Blueberry Soup

1
Bring first 7 ingredients to boil in heavy medium saucepan over high heat, stirring until sugar dissolves. Reduce heat to medium-low and simmer until berries are very tender, about 15 minutes. Discard lemon slices and cinnamon stick.
2
Puree half of soup in blender or processor. Transfer all of soup to medium bowl and refrigerate until very cold. (Can be prepared 2 days ahead.).
3
Divide soup between 2 bowls or large goblets. Serve with lemon wedges and dollop of vanilla yogurt.