http://www.scirus.com/
Scirus has been developed specifically to search for the scientific information. It searches over 250 million science-specific Web pages. It does not index websites containing non-scientific content. This very feature particularly differentiate it from the market leaders in this area. Its key features include:
QUOTE
* Searches the whole web including access-controlled sites
* Skips websites without scientific content
* Covers more than 167 million science related pages
* Finds more peer-reviewed articles than any other search engine
* Reads non-text files in PDF, Postscript and others
* Yields more precise results because it indexes complete documents
You can save, email and export the search results as well. Apart from that you can refine your search with a list of suggested keywords.
This search engine is particularly helpful for the scientists and researchers.
