Yesterday the kids and I got up to some fun making our own sidewalk chalk paint and defacing decorating the pavement outside our house. This is really simple to do. Just mix 1/4 cup cold water with 1/4 cup corn flour and then add some drops of food colouring (I used about 5 drops liquid food colouring but you'll need more if you use the all natural stuff). Then head outside with some paint brushes and go wild!
It's great because you don't need to worry about the kids painting themselves or trying to eat the paint (and let's face it, when you're working with children under the age of two someone is going to eat the paint!!).
This activity was seriously fun and so easy to set up, I totally recommend you give it a try.
I originally found the idea here.