The European Patent Office provides data on 50 million patents from 71 countries worldwide as of February 2005. Esp@cenet also provides full-text searching of US patents from 1920 - present.
The Industrial Property Digital Library (IPDL) provides public access to IP Gazettes of the JPO, including patents, applications and specifications.
The United States Patent and Trademark Office provides access to issued patents' full-text (since 1976) and full-page image (since 1790).