How do I change my profile picture, or avatar?
I have registered to stackoverlow using my open id and can't see how to upload an avatar, so is that possible? if yes, how?
The avatar is tied to your Gravatar account (if you have one).
More info on Stack Overflow deciding to use Gravatars: http://blog.stackoverflow.com/2008/06/gravatars-identicons-and-you/