Whizzy Tags for K2 articles is based on the popular Joomulus for K2 module by JoomlaBear. It creates a jquery-driven tag cloud based on tags from a selected K2 category, which also allows you to specify the link, weight and colour of the tags.
Note this extension does not use flash, and it currently only allows the selection of ONE CATEGORY.
It also creates a search engine friendly list of tags, which is displayed in the event that jquery is not available in the browser.
If you're using Joomla! articles, please check out our Joomla! articles version which you'll find under the category of Search & Indexing>Tags & Clouds.