I came across Market Visual Knowledge Maps this morning. It claims to still be in BETA, and it maps business relationships based on companies or people that you enter. It seems to build these mind maps on the fly, and saves any maps that you have build so you can retrieve them later.
It's a service you have to pay for, but if you're looking through annual reports and SEC filings to find people and connections, this will save you a bunch of time. There's a fully interactive sample map, as well as an introductory video.
