1. In small saucepan, blend sugar and gelatin. Stir in water; heat over very low heat, stirring constantly, until gelatin is dissolved. Pour into medium bowl. Stir in evaporated milk and rum extract. Chill until semi-set, 30 to 45 minutes.
2. Using electric mixer at high speed, beat mixture until light and fluffy; fold in drained pineapple and coconut.
3. Divide mixture among four 6-ounce custard cups or individual souffle dishes. Chill until completely set, about 1 hour.