This is one of my favorites

Voki.com is a free online tool that allows you to create speaking avatars. Those avatars are stored online and can be shared in various ways. I like to use Voki to create announcements for my students when I am absent from school. I embed the Voki into my class site and the Substitute directs my students to go there. I would usually say hello, tell them why I was absent and that I had left assignments for them to complete with the Substitute. They always seemed to be nicer to the Substitute if they knew the information was coming from me.