VocabMonk is an interesting new site that I found out about from Larry Ferlazzo's excellent blog. This site uses a social network approach to help users build their vocabulary. The networking aspect makes it a great site for Social Learning, as well as being able to search forums, challenge others, and more. Also, this is a nice place to create a virtual "class" to help students learn via a easy to use word search engine.
I recommend checking out VocabMonk by clicking here!!!