The Cumulus Module in Drupal creates the funky flash(?) driven animated tag cloud that you see on my page. The instructions were pretty simple - to download the module and also download a cumulus.js file to the cumulus directory.
Thereafter, the really tricky bit was to find the 'number' of my tags vocabulary. When you're on your taxonomy page roll your mouse over 'edit vocabulary' for your desired vocab - in my case 'Tags' to find out which number it is (in this case #4).