FC,
If you're talking about the similies in my response, then you go to the reply screen and there is a section below the post window called "post options". Scroll down to it and check the box labeled "enable emoticons".
If you are talking about my little guy with the minigun avatar, go to the homepage and click on "my controls". On the left side under "personal profile", click on "edit avatar settings". In the center of the screen will be a section called "Your image avatars". I used the option to enter the url to my online avatar to keep from tying up the forum resources, but apparently you can also upload an image directly from your PC to the forum if you want.