If you use the "no-follow" tag when linking to a blog from your own blog article, does it still ping those blogs that you're linking you link to? [The hope being that those blogs might link back to you - hence developing your inbound links]
First of all, Nofollow is not a tag. Nofollow is the value of an attribute for an anchor. Pings, I believe are sent via a trackback Url and has nothing to do with a link inside the post. How search engines use a Nofollow link has been pretty much defined all over the place. The only question left is how does Technorati use it when they determine Authority, which is based on links. I have not seen the official stance for them anywhere, but people say they obey Nofollow as well. So I assume that it does not increase the Authority, if that link is to a blog that is claimed at Technorati.
Joel, There are legitimate reasons for using Nofollow. Sometimes you make a joke about some Poker site and link to it. You do not want the stigma of linking to a Poker site though. The page has to be worth linking to. To make a point or example that warrants a link, but yet not vouching for the link. Then there is the Wikipedia boycott (legitly so!) to Nofollow right back at them. In fact, I think there is a WP plugin that adds Nofollow to all Wikipedia links automatically! Kewl.
That's a point indeed. I stopped using nofollow long ago. It can give you too much comment spams. So, you can't impart comment link juice to honest people. It's sad that spammers are there always!
I understand why to use them, but I think he was talking about nofollow linking to other sites to get them to link back.