Fellow CRS espcrs twittered this site which includes 14 interesting uses for Wordle in the classroom: 

14 Interesting Ways to Use Wordle


Wordle is perfect for those visual learners who may find it easier to draw connections and semantically process information by viewing words in tag cloud form.  The slideshow created by Dai Barnes provides great examples of using Wordle to create quizzes, conduct author studies, improve essay writing, and facilitate student self-evaluation of performance or work.