(updated 9/28/07) I decided to put the recipe I used here... it was really good, pretty light, but really yummy and easy to make!
1- package yellow cake mix
1- 11oz container of mandarin oranges (with juice)
1/2 cup vegetable oil
2- packages of vanilla pudding mix
1- container of French Vanilla whipped frosting
9oz CoolWhip thawed
8oz crushed pineapple (drain juice)
Preheat oven to 350 degrees. Grease and flour 3 9" cake pans. Mix together cake mix, oranges and juice, eggs, oil, and one package of the pudding mix. Make sure to beat well so all of the oranges get crushed up and spread around. Divide into pans, and bake for 20-25 minutes, use a cake tester to make sure it's done before you take them out! Cool cakes in the pan for about 10 minutes, then turn out onto cooling racks.
For the frosting, combine bought Frosting, Cool Whip, Pineapple, and vanilla pudding mix. You may want to refrigerate the frosting before frosting the cake.
Frost between layers and around cake quickly to prevent melting, and then store in a fridge before serving.