Blueberry-Lime Granita

Process blueberries in a food processor or blender until smooth, stopping to scrape down sides. Add sugar, lime rind, and lime juice; process until well blended. Pour into an 11- x 7-inch baking dish. Stir in soft drink. Cover and freeze 8 hours. Remove from freezer; let stand 5 minutes.

Chop mixture into large chunks, and place in food processor in batches; pulse 5 to 6 times or until mixture is smooth. Serve immediately, or freeze until ready to serve. Garnish, if desired.