Recently (Dec 2003) Gerard Sweeney of The Tipshop fame created the Speccy Search Bar for Internet Explorer. I decided to attempt an equivalent for mozilla based browsers. SpecSearch also works on Opera (tested on Opera 7 for Linux.) Setting it up in Opera is much the same as mozilla.
The links below require you to enable JavaScript. To use them drag a link to your shortcut bar (the one with 'Home' and 'Bookmarks' on it.) You can now perform a search by clicking the link and entering your search criteria or by selecting text on any webpage and clicking the link to search for the selected text.
You can add these links as a drop down menu by creating a new folder in the toolbar and dragging them in. Alternatively you can manually add entries to the bookmarks.html file under the 'Personal Toolbar Folder' entry like so:
Sample bookmarks.html