Here are a couple of my favorite calendars for the classroom:
Celebrating Children's Books
This is a great way to promote literacy in the classroom. Kids get excited each month when they recognize one of their favorite books. Here's how I use the pictures once the year has ended.
Food For Thought
Saxton Freymann's whimsical food sculptures provide smiles and wonderment as children try to guess which foods were used. There's also a mini calendar available for 2007.