The holiday season is upon us, and it is only 28 days until Christmas. I know this because I just downloaded X-MasTree, a freeware app that puts a Christmas tree (with optional Christmas countdown) on your desktop. X-MasTree has a surprising number of preferences for a one trick freeware app. You can choose the color of the tree, what kind of lights are on, whether those lights blink, and if you want a star on top.
X-MasTree 1.3 is a Universal Binary and requires OS X 10.4.