As an experiment, I created an avatar and recorded an audio message using voki.com, a free avatar creation site. I plan to use this message in the first week of my Social Science 101 online course.
Unfortunately, Voki limits recorded messages to 60 seconds each and does not provide for uploading of a photo, although it allows for uploading of the short audio recordings. A better, much more complete personal avatar service is provided by sitepal.com, but it charges about $10 a month or more.
Here is the link to my Social Science 101 introduction:
Here is the link to by Humanities 186 introduction: http://tinyurl.com/4exv2k9