With version 1.9 of DasBlog, which I run here, comes the ability to support Gravatar's out of the box. What are "Gravatar's" you ask? Simple, a Gravatar is a small image (80x80 pixels) hosted by Gravatar.com which a site can request of you given your email address. This allows blogs, for instance, to show an avatar of your choosing next to your comment without having to personally handle you uploading the file, trimming the image, storing the image, screening the image for "appropriateness", and so on.
Gravatar's have been around for a while, but for over a year they have not allowed new people to sign up for the service because they had reached the capacity of there existing infrastructure. Well they've completely redesigned for scalability and are back with style. You will see now that my recent responses to comments include my ugly mug as an avatar next to my comments, and if you'd like your face immortalized then all you have to do is go to this site and request an account of your own. Once you do, you'll instantly have you're chosen Gravatar available here, no more work required provided you left an email address with your comment.
The Gravatar team has a blog here so you can keep track of what they are doing.