Dissolve gelatin in water.
Mix it with pineapple, bananas, strawberries and nuts in a bowl.
Pour one-half of the mixture in a Pyrex type glass serving dish (the long, thin kind).
Put in freezer for about 15 minutes.
Remove from freezer and spread sour cream over top of mixture. (You may need more than 8-ounces here).
Return to freezer for 10 minutes.
Remove from freezer and pour the rest of the mixture on top.
Cover and refrigerate overnight.
Enjoy!