MedHunt uses both humans and web crawling to build its index of medical information. Searches can be narrowed by region, and a French interface is available.
Search4Science is a search engine put together by scientists for scientists. It shows -- if you enter simple keyword searches you're often presented with related scientific terms to expand or limit your query. The service is powered by Northern Light, so results are also clustered in Northern Light's Custom Search Folders.
A directory with links to everything Macintosh, including daily software updates, Internet and HTML resources, shareware, troubleshooting, programming, hardware and software vendors, and anything else Mac you can imagine.