The updates in Will Richardson's 2nd edition of Blogs, Wikis, Podcasts and Other Powerful Web Tools for Classrooms provide a lot of new information. Simply comparing the table of contents of the 2nd edition with that of the first (as I did), one might not appreciate all the updates contained in the newer edition
Richardson has now explored and explained the intricacies of social bookmarking tools such as Delicious and Diigo as well as visualization tools such as Flickr. He has also updated the chapters on weblogs and podcasting to reflect recent developments.
His book continues to be a stellar choice for teachers who want to enhance their teaching by utilizing web 2.0 tools to create more interactive learning environments for their students and it is rumored that a 3rd edition will be due out soon. Can't wait!