I thought I had a good grasp on tagging but I just read a blog on how tagging can increase your page rank and links. So now I am a bit confused.
Technorati Tagging-- Tags are indexed. Search engines pickup on the tags and use them in search engine results. Tags help to categorize the post and make it easier to find. Q...
Tags provide navigation (such as hyperlinks) to other content that is likely to be of interest to the reader. It is based on the social bookmarking web application del.icio.us and is deployed as a small piece of JavaScript code on your pages. The creator of a bookmark assigns tags to each resource, resulting in a user-directed, amateur method of classifying information. Because social bookmarking services indicate who created each bookmark and provide access to that person's other bookmarked resources, users can easily make social connections with other individuals interested in just about any topic.
Tags on the various services like technorati and icerocket work the same way. (Del.icio.us is a little different.) If you use blog software and it supports tagging, the tags are written out into a specific format in your site's RSS feed. Technorati has a good page about how to do tags if your software doesn't support them: http://technorati.com/help/tags.html