Here is a quick and easy cocktail to make for kids on special occassions and all you need is a can of grape juice concentrate from a can, ginger ale and ice cubes and blender.
For older kids and to make it look more like a cocktail, you can skewer marichino cherries, pieces of orange, lemon, or line on a toothpick and teeter it on the edge of the glass.
Blend 6 ice cubes, 1 can of the juice concentrate and slowly add the ginger ale and blend.
Once you get to the top you may need to wait 30 seconds or so for the fizz to settle before adding more ginger ale.
Continue to fill the blender until it gets to the top and continue to blend.
Once it is done, pour into decorative cups (we used plastic cups that we got on clearance after Halloween) and serve.