Tag Clouds are quite the Web 2.0 thing lately. Tags Everywhere is an extension for tag cloud enthusiasts. Period. If you like tag clouds, this is the extension for you.
When I installed the extension, I surfed over to Digg and immediately, the Tags Everywhere extension kicked in. Tags Everywhere fetches the actual web page behind the scenes and immediately displays a tag cloud of the most used keywords in the article.
Not only is this extension great for tag cloud-ing, but is phenomenal for SEO's (Search Engine Optimizers) as well. Why? Because in an instant, you retrieve your keyword density for a particular article on your site. If the site doesn't have a good word count or great keyword density, pepper your article with more relevant keywords to find the sweet spot for keyword optimization. It would work better if phrases were used as well as complete words, but that's a feature for later. ;-)
Tags Everywhere works with Digg, reddit, Major SERP's (Search Engine Result Pages), and works with other sites as well by displaying a tag cloud at the top of the browser window.
Personally, I am into tag clouds, but not as much as to include it on every single page I surf to. After using it more and more, I realized that I wasn't looking far enough ahead to see the full potential of this extension. Again, it's great for a particular niche of users: the SEO's. This extension provides a quick, simple way to find out your keyword density at a glance and a chance to improve your article to provide the best return in the search engines.
Tag enthusiasts and SEO's are probably the only ones to benefit from this extensions features, but will leave regular users a little annoyed as to "why these words show up at the top of my site?"