Take a look at Voki, a program that let's you customize an avatar and then make it speak by either recording your own voice or typing in text and allowing one of the built-in voices in the program to speak your words. The program has all kinds of applications, and it's enjoyed by both students and teachers alike. In fact, you need not be a student or teacher to use the program. Anyone with a message to convey can put words to action by using this avatar program.
Vokis can be embedded in blog posts and websites and shared via email and in many other ways. Recently, I read a blog post, "Have You Used Voki with Your Students Yet?" The answer for me is yes: I have used it in a variety of ways including posting one right here in this blog's sidebar encouraging visitors to post a comment.
So if you're looking for an easy-to-use, entertaining Web 2.0 tool that can serve multiple purposes, be sure to check out Voki.
Here is a another quick I just published.