It's called Cranberry Slush... Here's the recipe...
4 cups cranberry juice
2 cups fresh squeezed orange juice, strained
1 1/4 cups vodka
1/4 cup fresh squeezed lime juice, strained
1/4 cup orange-flavored liqueur (recommended: Grand Marnier)
In a clean 1/2-gallon cardboard milk container with a resealable pour spout (I just used a pitcher with a lid), combine all ingredients. Seal carton and place in the freezer until frozen solid. If desired, pack into a cooler to keep your picnic food cold and let thaw while enjoying the picnic. Drink when it has thawed and is slushy.
And, of course, I can't just follow a recipe- I used Bicardi O instead of vodka, just because I like it better- it's super yummy and nice to keep in the freezer for those lovely summer days!