Now many people join Do Follow movement and give comment on the do follow blog.. To join this movement is very simple, you just need to remove nofollow attribute on comment of your blog and tell the blog or site that have list of do follow blogs on their blog/site. You can search on google to know what the blog/site is.
By doing this you can also get traffic and also comment of your content for blogger who want their blog have higher pagerank. For your information Google will index website that don't have ofollow attribute on the link script. By default blog system will put nofollow script on the comment system so every link on the system will not indexed by Google.
By removing nofollow you must prepare getting huge comments on some article. Unfortunately some or maybe most of the comment just spam or one/two word comments like Good Article, thanks, etc.
So should I remove nofollow on my blog?
If you want to get many comments so this is one of good way. But if you just want to promote your blog, you can do in different way.
But if you still want to remove nofollow you can active moderation comment and approve only good comment. You can add notification that you just approve for good comment on your blog too.