Blackberry Lime Rickeys

2 C blackberries
2/3 C sugar
1/2 C lime juice
1 C gin
1 liter sparkling water
lime slices
ice cubes

In a blender, whirl 1 1/2 C of the blackberries with sugar and lime juice. Pour through a strainer to remove seeds. Stir in gin. Fill glasses with ice cubes, top with 2/3 C blacberry mixture, fill with sparkling water. Garnish with lime slices and remaining blackberries. For a non-alcoholic alternative, use 1 liter + 1 C gingerale instead of sparkling water and gin.