Tags are useful to feature in your blog posts as they help your blog be spidered and categorised by social bookmarking sites like Technorati, Del.icio.us and BlogMarks. Tag links usually look something like this:
<a href="http://www.technorati.com/posts/tag/bookmarklet?from=http://www.bloggerbuster.com" target="_blank" rel="tag">bookmarklet</a>. The most important feature of the tag link is the 'rel="tag"' part, which informs bookmarking services that the link is a "tag" and not just a regular link. Blogger labels are defined in a similar way. As you can imagine, it is a rather time consuming process to write out each tag individually, so instead I use a "bookmarklet" to do most of the coding for me.
Perhaps the best way to explain the difference is by example. Here are some original Technorati tags, as you may have seen at the end of previous posts (these will open in a new window, which you can easily close to get back to this page):
Now here are the same tags, revised so that they only return results from Blogger Buster:
The first set of tags returned results from all websites, whereas the second set returned results only from this site.
If you like, you can test my bookmarklet my clicking on the following link. A window will pop up into which you can type "tags"; then click "OK" to be presented with the code you can copy and paste into your blog post. Preview this to see the tag links appear in your blog.
Please note that your blog should already be indexed by Technorati for this to work. If you haven't already claimed your blog, do go ahead and do so at Technorati, as being indexed by this hugely popular site has great benefits for your blog!
I would like to point out that there are also other bookmarklets for tagging your posts, such as the excellent GreaseMonkey plugin for Firefox, and of course Oddiophile's classic bookmarklet. However, none of the other methods I have tried worked the way I wanted them to within my Blogger posts: the GreaseMonkey script came the closest, as it offered a way to search within Technorati tags assigned to your username. For me, this wasn't a viable option, as I have many blogs and I only wanted the tags to refer to this particular blog. Also, I find my method much simpler, and compatible across all browsers.
Your feedback is always appreciated, so please leave your comments and opinions below.