WordPress uses Gravatar for avatars. So you go to http://www.gravatar.com and associate an avatar picture with an e-mail address. Everytime you use any wordpress based-blog with that e-mail address attached to the wordpress account, you’ll see your gravatar.
Hopefully what I said makes sense. I personally find it a little odd and not straightforward enough for the average user, but it works.
See I’ve done all that – it worked with this site however it made no difference to my own blog. Unless it doesnt update old posts? Hmmm…
Aha! No it doesnt.
Thanks, I too find it quite a backwards way of doing it. Would be much simpler and easier to have an option to change it within wordpress although with using Gravatar you are able to use the same avatar without uploading new ones all the time (though out different blogs I mean).