This may be an embarrassingly stupid question, but try as I may I can't figure it out. How do you upload your own avatar picture? When I try to change mine, I'm offered a choice of pre-set avatars, but I've seen lots of people using avatars that aren't on that list. Idiot-proof instructions would be greatly appreciated!
Go to My Preferences link at top right of page, then click on My Avatar. Then there will be a box you can put a link to your preferred avatar in. You can use the Browse button to find that avatar on your computer.