This community uses both a profile picture and an avatar. The avatar is what displays next to your posts. The profile picture is only viewable from your profile page. You will need to upload two pictures. The following Web sites are good places to get started creating your avatar if you do not already have one.
Voki:http://Voki.com. You can change complexion, hair color, body size, shape, etc.
DoppelMe:http://doppelme.com/. You can create a cool graphical likeness of yourself, your friends, family or any group