I came across a useful website called DISQUS today whilst leaving a comment on a blog post.

DISQUS allows you to set up one profile for use when commenting on blogs so that you do not have to use a generic profile. It’s quite a handy free service if you (like me) have a lot to say and comment on a lot of blogs on a daily basis.

All comments and replies can be tracked through one single account and the service is totally free with no advertising used at all.

All major blogging platforms are supported and you can easily integrate the service into your own website or blog so that users can enjoy the same benefits.

Take a look: http://disqus.com/home/.