TagBulb is an ajax based search tool that lets you to search for tags from multiple Web 2.0 websites simultaneously. It supports tags from variousĀ websites like RawSugar, Grouper, Google video, Flickr, YouTube, Technorati, Indeed etc and many more are added continuously.
It provides categorical search of tags in various categories like images, videos, books, products, blogs, jobs, podcasts, bookmarks, questions, events and goals.
TagUniverse allows you to see tag cloud and to take a look on what the world is searching for.