This extensions lets you to easily switch between search engines directly from the new tab page
Search on top search engines with the Search Manager Chrome extension. You can easily switch between Bing, Google and Yahoo search engines directly from the new tab page.
Your search engine selection will let you search from both address bar and the new tab page, and allows you to quickly choose your preferred search engine without any trouble.
EULA - http://support.searchmgr.com/eula.html