You may have noticed that commenters with Typekey identities display a hyperlinked image beside their names: 
This icon, which is used to signify commenters authenticated via Typekey, is copied to your blog directory when you first publish your blog.
If you like to keep things pretty, you might want to replace the original image (a dark charcoal color... so utilitarian) with one that is color coordinated with your site. Customizing nav-commenters.gif to coordinate with your blog's style is a snap.
How? you ask...
If you want to edit the image yourself, MT's original typekey commenters icon can be found in /path/to/mt/mt-static/images/nav-commenters.gif or, of course, in your blog's root directory on your webserver. I simply opened the image in PaintShop Pro, increased the image's color palette to 16 million colors, applied the color-replace tool with my chosen colors and saved as transparent gifs. (It need not be transparent if you match image background with comment background.)
Upload your new image into your blogs root directory as nav-commenters.gif and you'll be good to go. :-)
For the pixel-challenged, I offer a few samples specifically coordinated to MT3.1's default styles (more for MT3.2 styles on the way):
(right click, save image as... you know the drill)
Chalkboard 
Gettysburg 
Independence 
Sakura 
Squash 
Alternatively, you can replace the original with any icon, such as the quill pen I use on my blog about my adventures as an interpreter of 18th century Virginia history:
In this case, simply name your image nav-commenters.gif and upload to your blog directory, replacing the original.
NOTE: Above instructions should still work for MT3.15 and earlier. MT3.16/17 serves one and only one icon to all blogs on an installation from mt/images. I added PublishCommenterIcon 0 to mt.cfg which disables icon on static archives. Replaced php/lib/function.mtcommentauthoridentity.php with 3.15 version to correctly map image to blog directory rather than MT directory. Hope that makes sense. Better yet, hope you'll upgrade. ;-)
