Digression: Google Desktop Search

Apropos of nothing: if you haven’t downloaded Google Desktop Search, go do it, right now.
It takes a little while to index your hard drive the first time, but after that, delivers unbelievably fast searches of all your files and, if you use Outlook, all your emails.
Working with the Ecosystem, I’ve developed a pretty healthy appreciation of search performance and indexing. And I can safely say I haven’t the foggiest clue how the hell Google Desktop Search does what it does.
This isn’t a reasonable evolutionary step towards better functionality/performance. This is, like, space alien technology. I have no idea how it works, but it doesn’t even appear to be playing by the same rules as every other search technology I’ve seen…