Just in case anyone wanted to know how to change their automatically assigned avatar, the image above explains how much more easily than I can. Text form for the image-bereft, though:

How to choose your own avatar:

• 1.) Make a comment. (This will 'log' you in. There might other ways of logging in, but I'm not really sure how. I swear this isn't a ploy to get more comments!)
• 2.) Go back to the post and view comments.
• 3.) Scroll to below the comment box.
• 4.) Click 'register your avatar'.
• 5.) ???
• 6.) Profits!

All avatars are courtesy of Pellissier, Ice Climbers, and Hakuryu from AnimeSuki Forums.
If there's a custom avatar you wish to add, please contact me using my e-mail address on the Contact page. 100×100 only, plzkthx.

Things to note:

• Avatars can only be chosen once. Once you choose the avatar, nobody else can.
• Avatars are linked to your e-mail address. So don't randomly switch e-mail addresses and wonder why your avatar changed!
• Once you choose an avatar, you will receive an e-mail asking you to confirm it. This is important!