1. Combine pudding mix, jello, and sugar in a saucepan. Stir in half cup of the water. Blend well. Add remaining water, and cook, stirring constantly, over medium heat until mixture comes to a full boil. Remove from heat. Stir in rum, then chill for about 20 minutes or until very cool. 3. Thoroughly blend cook whip into chilled mixture. Spoon into pie crust, and chill until firm, about 2 hours. 4. Garnish with additional cool whip and thin lime slices. Note: do not feeze this pie. Store leftovers in the refrigerator.