I enjoyed this article. For the desktop search tools, I was intrigued that you didn't mention X1. I have been using it for the past few years and it is terrific. It does not index the whole world, but its indexing and presentation for the hard drive is unparalleled. For instance, it finds the searched text and displays it on the right.
I installed Google Desktop, and after 36 hours, it is still indexing. It doesn't appear to be as efficient as I would expect.
Best wishes,
Mitchell