For the last few months I've been beta testing Classcraft, a site that helps teachers gamify their classes. So far I've only introduced the site to my astronomy class and one earth science course. I've made the greatest strides with Classcraft in my 9th grade earth science class. As you can see from the below video, they really get into it! Check out Classcraft to see what all the hype is about: http://www.classcraft.com/en/