The NoFollow attribute
When you comment on a blog and leave your own blog address you will get a backlink that search engines will pick up that will help you to increase your ranking. However, many blogs use the NoFollow attribute to make search engines ignore your backlink. They do this by including code like this:
href="http://www.rickety.us" rel="nofollow"
You can see it in a blog’s comments by using your browser’s “View Page Source” command. Blogger and WordPress both have NoFollow turned on by default, as do many other blogging platforms. Some blogs delay removing the NoFollow by a measured number of hours and others require a certain number of comments. I call these type of blogs restricted DoFollow.
Removing NoFollow
When I used to remove NoFollow from my WordPress blog I used the DoFollow plugin by Denis de Bernardy. I no longer remove the NoFollow attribute. This is purely an effort to reduce the number of plugins I use. Note that links placed in the body of the comment will still be NoFollow but the website listing typed into the website box will be DoFollow. Of course there is really no DoFollow attribute but if the NoFollow attribute is removed, the link is automatically followed.
Detecting NoFollow
The way I prefer to detect NoFollow is to use the Firefox SearchStatus plugin. Once loaded, when you go to comment you will see links that are NoFollow in a pink box. Very useful.
Finding DoFollow
There are a number of DoFollow directories that list DoFollow blogs. The problem is that restricted DoFollow blogs are mixed in with the the good unrestricted blogs. In some directories there are even some NoFollow blogs that slip through. Now that gets really annoying. So for a time I kept my own directories. With the SearchStatus plugin, when I came across DoFollow blogs, as I read the comments I would add them to my directory. Just surfing by a blog’s homepage that has Recent Comments displayed, Stylish will display the true colors of a commenter’s link.
A more direct approach is to use Google Image Search for “U Comment I Follow” (with the quotes). You might even want to make sure that the same text is displayed in your alt tag when you choose a DoFollow image for your blog.
Update
I have discontinued using the dofollow plugin to reduce the number of plugins I use.