inquisitor (deinstalled for keywurl)
is actually not a stand alone software. It's an enhancement for the Mac OS X webbrowser Safari.
While the search field of Safari lets you choose to search in google or yahoo, inquisitor carries that to an extreme. It starts searching while you type and not only in google, but in all webpages you configure. In the screenshot you can see the search result for "mind in a box" - a terrific music project. As you can see, the search result is not just a google result, but also a direct link to their webpage, to their music label, to a page called subKULTUR (never heared of that so far) three reasonable google links and amazon.de (a search engine added by myself to inquisitor)

inquisitor is freeware