on that page you can upload any picture and crop it to a square form (hold "shift" when selecting an area).. and save it on the required size (100 x 100 pixels)
If the problem is you can't find any image, just use your favorite character as avatar, I give you total permission to use any of my pics as your avatar.. actually it will be a honor ...I'm sure if you are watching me and reading this then something of my gallery took your attention, you can use it :D
If the excuse is that you want to use something more personalized.. something that you want to draw yourself and maybe just need to find some time.. then take this as a temporary avatar ^_^
Ps. if you like this info, please be my guest and share it on your journal
