Keotag provide a search engine for users to search through multiple social website and blog search engine like Technorati and delicious.
Keotag can search through 18 search engine and social websites including Technorati, del.icio.us, Twitter, Google, Digg, Yahoo!, Youtube, and etc. The search results are returned quickly and users can switch to other search engine without reload the page because Keotag use the AJAX technology.
To use Keotag, you can either type your keyword or simply pick any keyword from the tag cloud. After that, click on one of the search engine and the results will return shortly. Only one search engine can be selected at one time.
I think they should add feature for users to select multiple search engines and then display the result in tabs. This is not a must feature but i think at least user can compare the results between different search engine right? But Keotag has a very nice interface and easy to use since it is AJAX-based.