If you want to use your own avatar on this blog (and other) while leaving your comment, you need to have an account on Gravatar (Globally recognized avatar). This blog (as well as most WordPress blog) have Gravatar enabled.

To use it, you must first sign up an account on Gravatar website. Then upload your avatar image and you are ready to use your own avatar on any blog that compatible with Gravatar. To use it, you must use the same email when leaving comments as your registered email on Gravatar. Easy huh?