watermelon and lemon fizz


4 cups Watermelon, roughly chopped
Juice of 1 small lemon
30ml Vodka (more or less:)
10 Ice Cubes
Sugar to taste
Small Pinch Salt 
2 cups Sprite/7up
Blend together watermelon, lemon juice,vodka,sugar and salt till you get a thick puree.Chill.
Divide the puree into glasses and add sprite or 7 up just before serving.
Add  ice cubes and top with  lemon rings or watermelon cubes.
Serve immediately...