obba>Here are two great sites with good icons (or avatars):
1. original icons
2. buddy icons
The original icons is the place I go to, to change my avatars. I just stumbled upon the buddy icons and they also have good ones there. After you load the main page (original icons), look on the top and they should have some kinda search. Go to the "m" section, where the matrix should be. The other website, I dunno, just try to look for the matrix in there. If you find the one you want, just do the procedural thing, right click and save as.