Quick Google is a useful Chrome extension. You can search Google without leaving the current page and see a preview of each result.

KwiClick is an essential Firefox add-on for everyone who searches the web! You can search the internet right from your status bar, without leaving the current page.

There are several ways to integrate other search engines with Google result page. But, Matt Cutts has created a greasemonkey script for adding other search tools in the same manner as you may have seen in some April fool prank screenshots.

ChhotuGoogle is a nice tool to search in Hindi and Tamil. The site is powered by Google’s custom search and offers a very unique way to search in these Indian languages.

Sputtr is not a search engine, but a great  gateway to other search engines, blogs, services etc.

Frank Watson has noticed a change in the top search box of Gmail. The Search option is missing “Search Web” button!