Another cool search engine: PageBull
Came across the PageBull search engine via Lifehacker and I've been doing a little test searching today - it displays search results in a more visually oriented way than some of the engines, tiling images of the pages it retrieves for your search, so that you can get a better idea of what kind of hits it's returning.
Just tried this search on sensitivity and specificity and it seemed like it might be a better shortcut for this search than trying to figure out from the Google snippets what the pages actually cover. Results load a little slowly but it's an interesting concept. Plus I really dig the cute little PageBull icon :)
Some have suggested that this type of engine might be helpful in researching people - with the inclusion of the Varmus papers in the National Library of Medicine's Profiles in Science site this week, I tried a quick PageBull search for Harold Varmus, and was pretty satisfied with the results.