Loren Baker has a nice (even though common sense) link/digg bait list about how bad nofollow tag sucks. And they conclude that sucks. And it sucks very bad. And it sucks even in blog comments (imagine the horror):

1. NoFollow = NoWorky. Using NoFollow in blog comments, the original intent of the tag, does nothing to discourage comment spammers. Using other anti-spamming tools such as question, math and plugins such as Akismet and SpamKarma for Wordpress is much more effective.

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8. Commenting on a blog post is the same as adding more relevant to that blog post. A thought provoking one sentence post can lead to pages of comments. If someone takes the time to help build your site’s content via posting comments, it is professional courtesy to give them some link love.

But this is just another don’t practice what you preach article as they still have nofollow tags for thei blog comments.

Not anymore. Nice job and a good example (hopefully) for the others

P.S. I am still using it cause I am too lazy to remove them. But I will. I promise. I’ll stop procrastinating right now and install DoFollow