At this site you can download skins for versions 4,5&6 , you can download an avatar creator, cusom emoticon fonts and packs, add-ons and bots, a customizable away message. You can learn nickname tricks and use really funny random nickname generators like the harry potter edition and the pirate edition. You can also get an add-on that allows you to run multiple instances of msn messenger simultaneously, so you can chat using different msn passports at the same time! There is tons of other stuff you can learn how to do on this site, I've just listed the stuff I found so far.