There are plenty of stupid patents out there. Among them, software patents are probably the stupidest. There's supposedly a requirement that patents cover Novel
technologies or applications.
Amazon.com's one click patent is among the worst.
TheBrain's US6031537: Method and apparatus for displaying a thought network from a thought's perspective is almost as bad.
The Brain's patent could easily conflict with all existing mindmap or context-linking applications, including Everything2.
If you'd like to challenge a stupid patent, a good place to check is technocrat.net. Also see the Intellectual Property section of EFF