From the IP chapter:
There are two very good reasons to visit Mayall’s IP Links, from U.K. patent attorney John Mayall. The first is for its collection of IP links. It may well be the best, most thorough collection of IP links, all thoroughly annotated. It includes links to the patent databases of virtually every country in the world, to patent databases for specific technologies, to patent offices of many countries, and to non-patent prior art databases. Much the same is true for trademarks: links to trademark databases and trademark offices throughout the world. Most international IP laws covering patents, trademarks and copyrights are included, as are IP treaties and conventions. The site also includes links to databases for determining the status of a patent or trademark. There are even links to sites that can help track current IP-related lawsuits in the United Kingdom. As if these many libraries of links were not enough, a final category is for links classified as “None of the Above.”
The second reason to visit is to download and learn to use PatSee Patent Downloader. This is software—developed, as it happens, by Mayall’s brother—that manages the process of downloading patents from the Internet, automating many tasks, speeding download times, and delivering high quality images. PatSee actually hunts various Web sites for the patent you want, and then, when it finds it, downloads it page by page in .pdf format. PatSee is “shareware,” meaning you can try it free, and then pay for it only if you like it.
(Excerpted from the second edition of The Essential Guide to the Best (and Worst) Legal Sites on the Web.)