ConQuery
Context searching for everyone and URL manipulation tool for advanced users.Lightweight, fast and flexible - it allows to query web services by context menu of the browser. Queries may contain various parameters of curriently browsing web page: selected text, URL, host etc. Can be used for context searching and as well for working with advanced, complex web services.
Supported
versions: Firefox 1.5 - 2.0.0.* ALL Mozilla 1.4 - 1.8 ALL SeaMonkey 1.0 - 1.5a ALL Thunderbird 1.5 - 1.5.0.* ALL
Notes / Comments: * 2.0.0.* compatibility* bugfixes
Categories: Miscellaneous, Search Tools, Website Integration

ConQuery:

Right after installing to Firefox, Mozilla or Thunderbird -- ConQuery puts your regular searches to the context menu and allows you to search for selected text:

If no text selected, ConQuery acts as a list of shortcuts to the search engines, allowing you to enter search terms manually:

Tune up ConQuery for much comfortable and smooth work:
