Canadian Intellectual Property Office
At this site from Strategis you can look up patents, trademarks, copyrights, industrial designs and integrated circuit topographies registered in Canada.

Canadian Patents Database
Look up Canadian patent information at this database from Strategis Canada.

Delphion Intellectual Property Network
Search Delphion's extensive database for patents held by different companies. Check out their fascinating Gallery of Obscure Patents. An interesting site.

Free Patents
There is a debate going on over the extent to which software should be patentable. This site covers both sides of the debate. Note: In Canada software is covered by copyright and not patents.

Interactive Intellectual Property Guides
Strategis Canada offers several I.P. interactive guides here including a Patent Filing Advisor. 

Patents.com
The Florida law firm of Oppedahl & Larson LLP provides extensive information on U.S. patent law at this website.

RE$EARCH Infosource Top 100 R&D Spenders
RE$EARCH Infosource is a primary source for information on Canadian corporate R&D spending.

RE$EARCH Infosource Top 50 Research Universities
In the fall of 2001 RE$EARCH Infosource will start listing the top universities for research and development.

United States Patent and Trademark Office
Lots of information at this official US Patent Office website including how to apply for a patent and status of your patents if you have any.

Technology Review Patent Scoreboard
MIT's prestigious Technology Review lists the top patent holders in eight industry categories.