Patents and Trademarks

US Patent Database includes searches including trademarks. From United States Patent and Trademark Office. This system provides an interface to search a database of U.S. Patent bibliographic data from 1976 to entries posted within the past few days. Try a search on "ink jet".
Strategic Patent Web Site - IP Resources (dead? 12/30/04) provides world references concerning intellectual property. From R & J Patent Drafting, a patent service.
US Patent Classes offers an index to the US patent classification system by subject area and retrieval of patent numbers and titles. From UNC MetaLab.
STO's Internet Patent Search System allows one to determine patent class using a Manual of Classification, determine patent class using a subject Index to Classification, retrieve patent titles using class/subclass code and retrieve patent abstracts using patent number. From UNC MetaLab.
World Intellectual Property Organization offer information in English, French and Spanish on their activities plus information on conferences and WIPO publications. Includes details of patent, trademark and copyright protection treaties.
Derwent provides a lot of background information on patents as well as details of their patent information services.