Also on these boards
Adding hearts to the grinch (scroll down in blog) when students demonstrate an act of kindness. LOOOOVE this idea.
Cumulative - (This is the site, not the actual page - couldn't find picture on that page that was big enough.) "Our Knowledge is Piling Up" snow bulletin board - could put different units we've completed with summaries of each on them on snowflakes, or have students write on snowflakes what they've learned and pile them up across the bottom of the board