Here's the one I made this year: Countdown Calendar
And here's a different spin on the idea that I saw on MacKenzie Bruckler's blog this morning: Countdown Banner
My kids started their countdown this morning with a treasure hunt. (The drawers are too tiny for gifts, so I will put clues to gifts that are hidden somewhere in or around the house.) I wrote a short poem with the clue, and then they took off to find it.
Incidentally, my family just got into geocaching, so I might hide some gifts in the yard, along with coordinates, and let my kids search outside too. Anything to trick them into getting exercise! LOL