This plugin for WordPress 2.0+ provides a neat way to create tags for each of your posts, based on the first time you save the post you are writing. Here is the text taken from the Autometa website:

Automatic Tag Generation

This plugin will automatically generate and include HTML Meta Tags and Technorati Tags based on the full text of your post. When you save your post (and before you publish it) the plugin checks to see if any tags have been associated with it.

In fact, this tool works very well. It’s simple to install, requires virtually no configuration to get started. But here’s the biggest HOWEVER. If you use it to create automatic tags, you may find that there are some problems:

• it tags based on your post’s first save only;
• it creates tags that may not be appropriate; and
• you NEED to edit the tags for EVERY post.

The actual editing of the tags is relatively straight forward, too. In your blog page creation space, just scroll down until you see ‘Custom Fields.’ That’s where you edit your tags. It takes but a few seconds, and the results are well worth it.