Feel free to update your avatar image in the User Control Panel (Hover over your name on the top of the page and you'll see it). Go to Profile, then Edit Avatar.
This board is hooked up with Gravatar, an on-line service you can use for free to control your avatar image everywhere on the net. Go to http://www.gravatar.com and create a new account, then assign an image to your desired email address - badda boom, you're done. Now anywhere you use that email you'll see your gorgeous mug-shot (or what ever photo you decided to use). Makes it easy to change your profile photo.