If you have made mistakes, even serious ones, there is always another chance for you. What we call failure is not the falling down, but the staying down.
Anyone can have one. It's actually handled through the community builder section of the site (and integrated into the forum). If you click on the "My Profile" button to the left (in the User Menu section when you're logged in), you can update your image there through the Edit drop-down list above your profile (and it will create a message board avatar from your profile image). You can also edit your profile there to provide a homepage link, bio, and message board signature (please try to keep images in your sigs less than 450 pixels wide to prevent messing up the forum formatting).
I'm currently working on adding a customized tab section to the profile area that will allow registered members to put up writing samples (to allow people to use their profile page as sort of an online resume).