Use these to make your own avatars and icons!
(In .bmp format so that they can be edited in MSpaint too.)

16×16: favicons (the little icon some websites have, that can be seen in the address bar or on tabs if your browser uses them)

32×32: Windows XP icons (to decorate the shortcut folders on your desktop for example) or Website link button for affiliates

88×31: Website link button

50×50: can be used as avatars on AIM (an instant messenger tool) or on DeviantArt for example

64×64: the maximum size your avatar can be on Subeta.org

100×100: common size for MSN avatars (another instant messenger tool) and LiveJournal icons

(Note to self: add 125×125 template for forums and message boards)