It seems like a good time to post a link to one of my more popular posts: Cookie Sheet Advent Calendar.
A shot of the Advent Calendar with all the numbers magneted on. Click the image for a closer view.
A shot of the Advent Calendar with the magneted numbers removed - behind each number is a small printed photo from past Christmas celebrations. Just like above, click the image for a closer view.
Feel free to share links to your advent calendar examples in the comments below!