Easy to make, Fun to play with and Safe for the kids, here's a recipe I received (with thanks!) from our local Ontario Early Years centre. 

• 3 cups of flour
• ½ cup of salt
• 1 Tbsp of alum or cream of tartar
• 3 Tbsp cooking oil
• 1½ cup hot water
• food colouring or koolaid

Combine dry ingredients, stir. Combine water, oil and colouring in a measuring cup. Add liquid to dry ingredients and stir. Mix and Knead well.

Store in an airtight container (like Tupperware!) :)