Halve pineapple lengthwise through crown. Using paring knife, cut out and discard core running down center of each pineapple half. Cut out pineapple from shell halves in large chunks and reserve ( use a grapefruit knife, if you have one, since it cuts out hte fruit more easily ). With spoon, scrape out fruit and excess juice from bottoms of shells into 1 quart glass measure, leaving 1/4 inch thick pineapple boats, which will become serving containers. Blot boats with paper towel and place in freezer until frozen solid. Cut large chunks of pineapple into 1/4 inch pieces. Add to scraped pineapple pulp and juice in glass measure ( you should have about 3 cups ). In medium saucepan, combine pineapple mixture with 1/4 cup sugar and the rum. Bring to a boil over high heat, stirring. Reduce heat to medium and boil mixture until liquid cooks off and pineapple pieces are glazed-looking, about 30 minutes, stirring occasionally. Transfer to small metal bowl. Stir in lime juice and coconut flavoring. Refrigerate mixture until very cold, about 2 hours. In medium bowl, whisk together powdered egg whites and 6 tblsps warm water until egg whites are completely dissolved, about 2 minutes. Add cream of tartar. With electric mixer on medium-high speed, beat until soft peaks form. Increase mixer speed to high and beat in remaining 1/4 cup sugar, 1 tblsp at a time, until stiff and glossy peaks form. Fold egg white mixture into chilled pineapple mixture. Spoon into frozen pineapple shells and serve immediately. If serving frozen, place filled pineapple shells in freezer for several hours or overnight until mixture is semi-hard (mixture will not freeze rock hard ). Present in pineapple boats and spoon into dessert bowls. 161 calories; 2 g protein; 1 g fat ( 6% fat, 0 g saturated fat ); 31 g carbohydrate; 27 mg sodium; 0 mg cholesterol Recipe by: Richard Simmons "Sweetie Pie" Posted to MM-Recipes Digest by Nancy on Feb 2, 1998