Google's new Desktop Search software is a muscle car among search engines, racing through personal data stored inside your computer to instantly find things you can't easily locate.
But it's also capable of skidding off the road when driven without the appropriate degree of caution.
Introduced Thursday as a free download, Google Desktop Search ( http://desktop.google.com )
keeps track of files on your computer's hard drive in much the same way that regular Google finds information you want on the Internet.
When you go to the Google search page in your browser, after installing Desktop Search, the first results you see are your own files.
If you're searching for information about Sunnyvale, for example, you get a list of e-mails, Word documents and plain-text documents on your computer that contain the word "Sunnyvale."
On my home PC, the first hit was an e-mail message from a friend about local politics, including a reference to that city. Below the Desktop Search results were the Web search results, starting with the city's official home page.
Suddenly, I no longer have to ponder where I saw some piece of information: In an e-mail? On a Web page? In a document? A single Google query now covers everything I've seen on my computer since installing Desktop Search, as well as whatever is available on the Web.
This is hugely valuable, yet occasionally creepy.
Desktop Search does three things in particular that could compromise your privacy when someone else uses your computer:
First, the software keeps a copy of all your AOL Instant Messenger conversations. AIM, for many users, is like talking over the water cooler at work -- you say things you don't want preserved for posterity. Until now, AIM conversations with your buddies disappeared from your computer the moment you closed the discussion window. Desktop Search, however, makes a copy of AIM conversations and keeps them forever.
Second, the software keeps its own copy of all your Outlook and Outlook Express e-mail messages -- even after you delete them from within Outlook or Outlook Express. A confidential company memo, in other words, will still pop up during Google searches after you've emptied the Deleted Items folder in Outlook.
Third, the software keeps a copy of every Web page you visit and lists those pages in search results with the date and time of your visit. This even includes Web pages that are supposed to be secure from prying eyes, such as those run by online banking sites.
That means if someone else uses your PC and enters the word "bank" or "brokerage" in Desktop Search, they could uncover your confidential financial information. There are controls within Desktop Search to block each of these three search features, but it's not immediately obvious how to find them and many users will never bother to learn.
On the other hand, many users will find these same features very useful. If you're getting important work or school information through IM, not just gossiping, the Desktop Search archive could be a lifesaver. Similarly, we've all had the experience of accidentally deleting an important e-mail, or being unable to find our way back to a crucial Web page.
I called several experts on Internet security and privacy Friday to see if the far-reaching power of Desktop Search would stir up controversy. The consensus, for now at least, is no.
The experts know, better than the rest of us, how many threats exist in malicious software that hides its intent to steal personal information. Google Desktop Search, at least, doesn't disguise itself. The program shows its presence with a small icon in the Windows system tray that looks like a child's swirly lollipop.
My bottom line: I wouldn't recommend installing Desktop Search on any computer you don't own, such as PCs at work or school. If you think there's a risk of strangers using a machine you do own, disable the part of Desktop Search that keeps copies of secure Web pages -- but keep the other parts.
Desktop Search is officially a "beta," or unfinished pre-release program. Usually, software stays in beta for only a few weeks, but Google routinely runs beta programs for months or years. That gives the Mountain View company room to make improvements, and Google has already said it's working on password protection -- so only you or anyone you give your password could search your personal files.
Despite the beta status, I would recommend Desktop Search now to anyone who's having a hard time keeping track of the many types of information that accumulates on a computer.
You'll need a PC running Windows XP) or Windows 2000 ) with 500 megabytes of free space on the hard drive. Desktop Search doesn't work with older versions of Windows or the Macintosh.
You'll also need to be patient at the start. Desktop Search works in the background to keep an index of your personal files, and requires five to 24 hours of computer running time after installation to fully catalog your hard drive.