Creating Passionate Users is a website created by Kathy Sierra, one of the people responsible for developing the Head First Style of books available from O'reilly. Head First takes difficult subjects and presents them in an engaging way. I have several of the Head First books and enjoyed them thoroughly. I think many of the techniques used in the books would be beneficial in any classroom: use of pictures, redundancy, emotional content, conversational style, challenging activities, and hitting multiple learning styles.
Creating Passionate Users has all kinds of useful ideas and examples based on her experiences and feedback from the Head First books. Unfortunately, she stopped posting to the blog in 2007, but the posts are still valuable.
[Image captured from Head First Labs: http://headfirstlabs.com/books/hfwd/]