Is tagging really worth the trouble?
I've played with tagging a bit, including embedded Technorati tags and explicit tags entered using Blogger's post editor, but I think I've all but concluded that they aren't worth the effort. You already get most of he benefit of tagging due simply to the way search engines index your web and weblog pages. Explicit tagging does provide a little extra oomph for raising the ranking of your content, but not very much, and it is debatable whether you get any noticeable benefit at all. My conclusion is that it is doubtful that an average blogger will get any detectable benefit at all.
There may be some niche situations where explicit tagging does provide significant benefit, but it seems clear that those would be the exception rather than the rule.
I actually haven't bothered to do any explicit tagging at all in the past few months. I'm content that people may only find my content by searching for tag terms in a search engine.