Smoothies are great - they're refreshing, children love them and they're an easy way to get everyone eating more fruit. They include the whole fruit so the vitamins and other nutrients are in a very natural form, combined with the fruit's fibre and this means that they cause fewer fluctuations in blood sugar levels.
The other bonus is children tend to like smoothies made of fruits that they would otherwise not touch, so by drinking them they get used to a larger variety of real fruit tastes.
You don't have to have a special smoothie maker - a liquidizer or a hand-held blender works just as well. Simply throw any fruit that you have in the kitchen into a container and liquidize. You can jazz up your smoothies by adding different milks and yoghurts. Again it's a great way to introduce other forms of non-dairy milk just to add a little variety into their diet.