Avatars

In computing, an avatar is the graphical representation of the user or the user's alter ego or character. It may take either a three-dimensional form, as in games or virtual worlds, or a two-dimensional form as an icon in Internet forums and other online communities  
http://en.wikipedia.org/wiki/Avatar_(computing)

Here are some examples of Avatar creation tools.

VOKI
Create speaking avatars with this great tool. You can embed them in your blog or website. See example here.

VYOND
You can make animated videos with avatars you design yourself.

DOPPLEME
Create a graphical likeness of yourself for use as an avatar in forums, blogs, websites and almost anywhere else on the web.