I got this from Miserly Moms. I have been craving slurpees lately and this hits the spot for me.
4 cups ice cubes
1 1/2 cups water
1 package Koolaid, unsweetened, any flavor
3/4-1 cup sugar (I have used Splenda)
Place all in blender, water first. Blend on low speed, gradually working the speed up to high. Blend from 1-3 minutes. Serve immediately.