To change the layout, color, or background, or all of them, a good website is Coolchaser.com. Go to one of the blank profiles and click Layout, then search what you want as your layout and when it...
To change your default photo, click on the arrow to the right of the "Profile" link at the top of any page. From there, click on the "My Photos" link (or go to your own profile and click your default...