I just love smoothies and frozen drinks. Much healthier than a malt or ice cream and if you freeze a little tub of yogurt, it will feel like you are drinking something high in calories and processed sugar, but you are not. If you like, add a little ice to the mixture for a more slushy consistency.
Combine yogurt, berries and bananas into blender, cover and blend till desired consistency. Add milk, extract, sugar or splenda and blend again. Can add a few ice cubes into blender or serve over ice if you wish.