Blend cream cheese and butter or margarine. Stir in flour just until blended. Chill about 1 hour. This can be made ahead and chilled for up to 24 hours.
Preheat oven to 325 degrees F (165 degrees C).
Shape dough into 24 one-inch balls and press into ungreased 1 1/2 inch muffin cups (mini-muffin size) to make a shallow shell. Fill with your favorite filling and bake for 20 minutes, or until light brown.