If you are in a hurry or don't have the right ingredients, here's a very quick version of playdough.
You will need:
2 cups white flour
1 cup water
Mix em together! If it is too wet, add more flour. If it is dry, add water a few drops at a time.
Add a teaspoon of kool-aid or similar for coloring if you like. This won't keep well and, to be honest, isn't as good as the cooked version, but it's easy and fast and the kids can make it themselves.