A company called Devon Technologies is marketing a personal search engine that is supposed to discover associations for you. I downloaded it and tried it for all of 5 minutes, and I don't think it does what I want. It seems to be quite manual, whereas I believe that software to do this needs to be 100% unguided and automatic. I shouldn't have to hand feed it, that's just too hard. So it's no Google for the desktop, yet.
I suppose I should feel good about myself, since I had this idea back in August 2000, and wrote about it in my data links paper (badly needs some editing). However, what it really goes to show is that I should have taken the idea and ran with it.