ZoteroBib is a free service that helps you build a bibliography instantly from any computer or device, without creating an account or installing any software.
You can use words or symbols called search operators to filter your Gmail search results. You can also combine operators to filter your results even more.
How to use a search operator Go to
Paperscape is a tool to visualise the arXiv, an open, online repository for scientific research papers. The Paperscape map currently includes all (non-withdrawn) papers from the arXiv and is updated daily
eTBLAST is a unique search engine for searching biomedical literature. it lets you input an entire paragraph and returns MEDLINE abstracts that are similar to it.
Scirus is the most comprehensive science-specific search engine on the Internet. Driven by the latest search engine technology, Scirus searches millions science-specific Web pages. Scirus has proved so successful at locating science-specific results on the Web that the Search Engine Watch Awards voted Scirus 'Best Specialty Search Engine' in 2001 and 2002 and 'Best Directory or Search Engine Website' Web Award from Web Marketing Association in 2004, 2005, 2006, and 2007