A lot of people use Blogspot or Blogger blogs and they want to share the luv too!
Intense debate is a free commenting system by Automattic (the people behind wordpress). It works on most blogging platforms and can transform the way you debate on your blog.
Commentluv is now available as an IntenseDebate plugin and can be activated through your IntenseDebate dashboard.
See this excellent step by step tutorial on how to install CommentLuv to Blogger