scitopia.org

A user-friendly federated search engine for researchers/engineers from science societies have arrived.
http://www.scitopia.org

The new search portal scitopia.org was created through the collaboration of 15 leading science and technology societies including IEEE, OSA, APS, ASME, SPIE, SCIAM, etc. Search results are categorized among papers, patents and government documents (grants, etc.)

Google Patent Search

Google has announced a patent search engine. All patents available through Google Patent Search come from the United States Patent and Trademark Office (USPTO).

http://www.google.com/patents