1)   Re-Search 1.10
Re-Search makes your search easy, fast and effective. You can search information on the web with more than one search engine simultaneously. You can not only choose the engines but also add engines you'd like to use.

 2)   Search Engine Explorer 4.1
Search engine explorer is a multiple search engine search tool. It allows up to 20 search engines to be running and searched simultaneously. The gruelling task of having to switch between search engines can be completely eliminated.