You may have noticed that at the bottom of the posts on this site that there is an “About the author” section.
In the past I’ve been asked how this was done, and the truthful answer is that it is part of the TwentyTen theme and was already there when I installed WordPress 3 for the first time.
The clue is the content is option “Your Profile”, on the sidebar when you are in the WordPress dashboard.
It is the “Biographical Info” that provides the text information and the photo is provided by Gravatar using the e-mail address of the user account.
This makes the feature really easy to use, and if you are using the TwentyTen theme it does not require any further coding.