I just wanted to post about Commentluv blogs for those of you who have not heard about them.
If you are looking to increase your backlinks by blog commenting, then it only makes sense to comment on dofollow sites. Most sites that use Commentluv are dofollow. The benefit of a site using Commentluv is, when you post a comment, Commentluv automatically reads your rss from your site and posts a link to your most recent post. This link is a dofollow link in most cases.
So in closing search for Commentluv enabled sites and you will get dofollow backlinks. In case you haven’t noticed this site has Commentluv enabled, so feel free to comment for a backlink, but make sure the comment pertains to this and every post.