But why use them?
Studies have shown that when a learner sees and hears a person like figure in an online lesson, they try harder to learn and understand the information being taught. Some companies have used sites like Second Life to create whole corporate worlds where their employees can connect, communicate and learn using avatars to represent each person.
A lot of people think that creating and using avatars is very expensive, but now there are some really good forms of software out there that does a lot of the work for you.
Take Media Semantics for example. Their software lets you build and add avatars to many learning programs and presentations for less than one thousand dollars (cost of software, voices, etc).
Here is an example of one learning module I created incorporating an avatar. It uses my voice for audio instead of text-to-speech. H1N1 Awareness