Many users have been using the Ultimate Tag Warrior plugin in their WordPress installation to have tag management in WordPress versions before the latest release 2.3. The problem is that version 2.3 does not support the UTW tags. There is an option though to import UTW tags in the built in tag system. Remember to import tags in parts of 1500 tags (if you have more than 5000 tags). After importing the tags you can add the tag cloud widget in your sidebar.
If you want to embed the tags in your theme, you need to modify index.php and single.php. Just copy the following code
<?php the_tags(‘title’, ‘separator’, ‘end’); ?>
and paste it under the <?php the_content(); ?>. Index.php is the main page of your blog. Modify single.php if you want tags to appear also when viewing single post pages. Where title, write what you want to appear before tags (in my blog that is Tags:), where separator write what you want between tags (here it is “,”) and where end write what you want to appear after tags (I’ve left it blank as I do not want a word after my tags).