Preheat oven to 400 degrees.
Heat water and butter to a rolling boil in a saucepan. Stir in flour all at once. Stir vigorously with a wooden spoon over low heat until mixture no longer sticks to pan and forms into a ball. Remove from heat. Using an electric mixer, beat eggs in thoroughly, one by one. Beat mixture until smooth. Spoon cream puff mixture into a pastry bag fitted with a plain tube and pipe the equivalent of a tablespoon onto ungreased baking sheet leaving 3 inches apart.
Bake for 15 minutes. Reduce the oven to 350 degrees and continue baking until puffed, golden brown and dry.
Whip the cream with sugar and instant vanilla pudding until stiff. Fill the puffs with cream using a pastry bag fitted with a small plain tube. Other fillings can be used (ice cream, chocolate or vanilla pudding).