I was going to suggest a cardboard cone, which can be found at many different craft places, but that looks real cool Stu.
If you choose to use the cone method, you can wrap your truffles in colorful foil (I'm a redneck and like shiny things), and then use "sticky dots" to fix them to the cone.
Another idea is to check out the website at www.sunflowersugarartusa.com They have edible glitter that we use in our shop for "blinged out" lollipops. You could roll your truffles in glitter too for your tree.
...but I DO like the one in the photo that was just posted. Probably the nicest I've seen yet.