Yahoo Desktop Search (a rebranded version of X1) has launched.
Yes, Google, MSN, Ask Jeeves, and others already have free desktop search downloads. Here's another to throw on the pile.
In an excellent and detailed review of Yahoo Desktop Search, Chris Sherman makes the interesting point that "missing from YDS is one of the most useful features of Google's desktop search -- the automatic indexing and caching of web pages you've viewed with Internet Explorer."
Without search over your browse history, desktop search is merely a fix for the dismally slow file search built into Windows.
But search over the browsing history moves desktop search toward Memex, the memory extender. It would allow you to recall anything you've seen on your computer before with the touch of a button. That's where Google is headed.
See also my comments on personalized desktop search (Blinkx, Dashboard) in my earlier post, "MSN desktop search", and my comments on the limited business prospects for desktop search in "Mamma buys Copernic".