For the chatbox, you are able to load your own if you are able to find the url for it and load it into the email/url space above the message typing box.

For Front Page postings/comments, however, only I can add a user’s avatar, unfortunately, so if you tell me what avatar you want, ie the url for it, or a picture you have posted on the Front Page, or the one you use in the chatbox, then I will add it for you, once I’ve noticed the request. Obviously, if I haven’t done it a few days after you’ve asked, chase me up.