So EASY! I just happened to find the idea one day on Disney's Family Fun site. All you need are some paper plates and a stapler. (I used dessert size plates for these.)
I also had a pineapple out. Very original, right? But, it did add to the atmosphere and it was very yummy to eat afterward.
I had really wanted to make a couple of palm trees for the party, too. Since rain was in the forecast, I didn't want to spend all the time and effort on them and then have them ruined. Here's a cool tutorial for palm trees. Of course, there was no rain that day, so my concerns were pointless. Maybe I'll get a chance to make them one of these days for something else.