This recipe is in a church cookbook from a small town in Kansas. I haven't tried it - but if it works, it looks like it would be great fun for kids!
Ice Cream in a Baggie
1/2 cup milk
1 Tablespoon sugar
1/8 teaspoon vanilla
In a small Ziploc bag mix ingredients, zip shut. Fill a gallon size Ziploc bag with ice and 6 Tablespoons salt. Place small bag into large bag and zip shut. Shake bag until mixture sets up, about 5 minutes. Remove small bag from large bag, wipe off. ENJOY!