Most of the people living online are recognized by the avatar they use. Like nicks, avatars have become a very creative genre. There are many different ways; one of the best that I use id Gravatar. Set your avatart there and it will automatically surface when you use a particular email while putting your comments on any blog.
Now on, when you leave a blog comment, your avatar image will automatically follow you there and post a picture next to your comment. It is recommended to use the same avatar that you use on Twitter and your other social media sites since your blog comments are an extension of your personal brand (though I am still using different).