• Prepare the simple syrup by combining the sugar and water in a small saucepan - bring to a boil and stir until sugar is dissolved. Chill for several hours.
• Place the blueberries in a deep bowl and crush with a hand blender, or a potato masher. Strain into a bowl, pressing on solids to extract all the juice, and keep in the fridge.

For each drink:

• In a cocktail shaker, add a handful of ice cubes, 1/4 cup lime juice, a tablespoon of simple syrup, 3 tablespoons blueberry juice and 1 jigger of vodka. Shake vigorously, and empty into a 16 ounce glass. Add a few more ice cubes, and top off with lime seltzer. Garnish each drink with a few whole blueberries and a couple slices of lime. Serve with a straw.