At the end of the year, you could get a great big piece of white paper and have the students create a timeline of the school year from August/September- May/June/July.

Then they could decorate it and you could hang it inside / outside the classroom and have everyone enjoy it!

Lee has commented on this idea:

How about instigating this at the start of the year and adding to it when a great event occurs? Children could be 'immortalized' upon it when they do something good and you could end up with several class years around your classroom walls as a reminder. I really like this idea and hope to use it once qualified.