1. For syrup, combine grapefruit juice, sugar and cinnamon in a saucepan. Bring to boiling; reduce heat. Simmer uncovered for 5 minutes. Discard cinnamon; cool syrup. Cover and chill syrup. To serve, fill four 8-ounce glasses with ice.
2. Add about 1/3 cup grapefruit syrup to each glass. Fill glasses with ginger ale. Stir gently. If desired, garnish with Florida grapefruit peel curls, edible flowers and fresh mint springs.