Pretty cool, if I may say so myself. (Disclaimer: I stumbled across the basic idea on the internet a long time ago, when I was trying to find out how to make radish roses. I can't find the site now to give attribution, and, frankly, I don't think mine is all that much like theirs anyway.)
It's easy, too. The most time-consuming part is stringing the cranberries and golden raisins, but it's not exactly difficult. You need:
a pineapple. Choose one with nice looking leaves, that grow reasonably straight up out of the fruit. Unless you want a realistically tilty tree, that is.
a green apple
dried cranberries (maybe a cup?)
golden raisins (maybe a 1/4 cup?)
thread and needle
clementines or other fruit, as desired
a paring knife
frilly toothpicks (optional)
1) Cut the pineapple crossways about 2" below where the leaves join the pineapple, more if you want a taller star. Take the part with the leaves and put it cut side down. Trim away the fruit to the base of the leaves, or a bit less (you can always trim away more, if you want). You should still have a 2" square or rectangular bit of fruit in the center. Shape this into a star the best you can.
2) Trim a bit of the base off the bottom of the apple so that it sits flat and is reasonably stable. Cut out the core. Shorten a few of the center leaves of the "tree" and wedge them into the apple to attach the tree to the base.
3) Dust the tree with powdered sugar. Try not to get any on the star.
4) String the cranberries and golden raisins on the thread, using whatever pattern you want. You could also string up dried apricots or bits of dried mango or whatever other fruit you think would be pretty.
5) Peel, core, and slice up the rest of the pineapple.
6) Arrange the tree (apple side down, obviously) on a tray with the rest of the pineapple and the clementines.
7) Drape the cranberry garland around the tree. If necessary, you can attach one end to the apple with a red frilly toothpick.