Have you ever seen Vivisimo? It's a meta search engine but it has a twist. Vivisimo is the parent company of Clusty. Vivisimo is the more up-scale of the two. What they both do is query a number of search engines (by default MSN, Lycos, Looksmart, Wisenut, Open Directory, and Ask Jeeves) and then cluster the results into groups. It really makes more sense when you look at it.
Here's a screen shot:
Over at the left are the "Clustered Results." You can see that I searched for "trackpoint keyboard usb" and got 155 hits. These occur in the following "clusters:" UltraNav (40), Reviews (27), Space Saver (21), etc.
Even neater is the "preview" feature. Each result has a list of options following it. One of these is "preview." What this does is bring up a portion of the web page that is referenced by the result URL. I've done this on the second result. Those of you with good memories will recall that Google had a Google Labs tool that did this also.
You can click on the clusters at the left to narrow the search. Often these clusters are nested with narrower clusters. It's like you kept adding keywords to refine your search.
I tend to use Vivisimo when I'm hunting for a needle in a haystack. It helps you quickly identify ever smaller result sets to crawl through.