Comment section is more important for blog to get more traffic.I have seen gravatar comment section in wordpress blog it is looking good.I was planning to use gravatar to my blogger blog but i came to know it won’t support blogger blog right now and it still in discussion stage.If you are using blogger blog then use the following comment section for blog.
Disqus is a best comment system and moderation tool for your site.I could see most of the blogs are using this comment section.Definitely it make good discussion for your blogs.it also supports major social networking websites like facebook and twitter.It is free also.
Just go to Following link to register for blog
IntenseDebate is an another best comment system for blog.It supports major blogging platforms like Blogger,Wordpress,Typepad,Tumblr and more.It will definitely increase your blog pageviews and community.
You can check features here.
Just register and installing is very easy it will only three steps.
Blogkomm is another method it will be in the form of commenting scripts.It will appear within your blog and below the posts.
Just check the url for how it look