After the initial enthusiasm of using Google desktop search, iam now figuring out that i do not have need for such a tool anyway. Let me summarise what i search on my PC on a day-to-day basis.
Source Code
I use cygwin for most of my dev work, and also various IDEs for building and loading code for my various target platforms. Most of these IDEs are good enough for searching source code symbols, and on cygwin, i have built up an useful array of small scripts over the years, which help me search source code without wasting a lot of time.
Documents
I have a huge collection of documents that i have managed to download during the course of my last five years of web surfing, which run into GBs of space now. Long before any of these search tools existed, i have made it a habit to properly organise my document collection into folders that make it pretty straight forward for me reach to a required document. Most of the older pdfs happen to be scanned images, which anyway Google search or the Windows built-in search will not be able help. And i have noticed that mostly i end up knowing whats the document title(or atleast part of the title) that iam trying to find in my collection, so Windows built-in search is fairly fast enough (if you enable the indexing service).

Now the other main feature that Google desktop search provides is the ability to search through my web browsing history. Call me a paranoid, but i have almost made it a habit to clean up my web history. my cookies folder, and my web cache every week or so, and so i dont have much use for a search tool there either. And even though the integration to the Google interface seemed like a cool feature initially, i have found myself too lazy to open up a web browser for just searching for a file. I guess iam too comfortable with locate, find and grep that replacing that with the desktop search doesn't increase my productivity even a little bit!