All the search engine giants have test sites to test their new features before introducing them to their main search engines. Google's test site SearchMash is loaded with features, such as video, images, blogs and text results all at the same time. That is it scores over other similar test beds.
Other search engines also have test sites, however, they are not as innovative as Searchmash. Yahoo's test sites are AllTheWeb and AltaVista. Microsoft's test site is Ms Dewey. And Ask.com's test site is Ask X.