For many people, Google first showed up on their computers as a lone item on a long list of Web bookmarks. Since then, it has grown to be much more -- an e-mail account, a browser toolbar, a photo album and a map of the world. Now the Mountain View, Calif., company is offering a program that can replace much of the Windows start menu, and maybe even the Windows desktop itself.

Its Google Desktop 2.0 software (a free beta-test download for Windows 2000 and XP is available at desktop.google.com) aims to be your first stop for information on and off of your computer.

It does this with an optional sidebar that hugs the right edge of the screen and provides quick access to various applications and data sources, such as computer files, Web searches, to RSS feeds and recent e-mail messages.

The sidebar automatically pushes other programs to the left to avoid overlapping their windows (a widescreen monitor will definitely help). It's designed for quick scanning, but if you want more detail -- such as a chart of a stock's recent activity, the first few paragraphs of a news report or the forecast for the next few days -- just click on one of the headlines and a pane will flip out to the left with the additional information.

As a result, Google Desktop looks and acts much like a portal site such as the My Yahoo home page -- except that it actually works well.

Unlike the portals, Google Desktop doesn't make you customize it. Because its search tools have already indexed the files on your computer, it has the information to guess which forecasts, stock quotes and RSS feeds you might want.

This is a beta release, so its guesses could be wrong. During my tests, Google Desktop picked the right weather forecast on two of three computers. On the third, it thought I wanted to see the temperature in Honolulu. Its stock-quote picks missed what I thought would be an obvious choice for me: The Washington Post's WPO ticker symbol.

At the end of the setup process, a screen -- headlined "Please read this carefully. It's not the usual yada yada" -- asks you to enable or disable what Google Desktop vaguely calls "Advanced Features." It explains that choosing this option will send anonymous records of your Web use to Google to allow Google Desktop to personalize the stories displayed in the sidebar's news panel.

With neither the "enable" nor the "disable" buttons selected as a default choice, it's your call. I opted out of this on all but one test computer -- mainly because the sidebar's Web clips panel does a much better job of pulling in relevant news.

Unlike other RSS readers, the software built into Google Desktop automatically subscribes to feeds whenever you visit sites that offer them. That solves two big problems with RSS: People don't know what it is and don't know how to subscribe when they do find one.

Using that component can yield some spooky "how did you know I'd need to know that?" moments. But the software's practice of grabbing every feed in sight quickly leads to overload. Instead of a clipping service, it can seem more like a lint filter for the Web. It's best to let it collect feeds over a few days, then prune the ones you don't want and turn off the auto-subscribe option.

The other sidebar panels vary in their utility. Beyond news, RSS feeds, weather, and stock quotes, Google Desktop includes modules that preview e-mail messages, display digital photos, hold text notes, link to recently used files and list popular Web pages.

The e-mail panel would seem most useful, displaying subjects and senders of new messages in such programs as Outlook, Outlook Express and Thunderbird (as well as Google's Gmail site). But unless your monitor is measured in feet, you can see only a few of messages at once.

You can set up filters to hide some e-mails, but a filter that worked the other way -- one that showed only messages that match your criteria -- would be more helpful.

The photo panel offers an ever-changing slide show of pictures on your computer and on designated Web sites but eats up a lot of screen space in the process. A panel called Quick View links to your choice of recently or commonly viewed Web pages and files. Having it show only files on your computer and ignore your Web history, however, would make it a faster, more accessible replacement for the start menu's "My Recent Documents" folder.

The What's Hot panel can provide the occasional surprise as it spotlights popular pages. So far, however, almost all of its picks have been obvious (for example, a BBC story headlined "Microsoft-Google battle heats up").

My favorite panel is the simplest: Scratch Pad, which lets you jot down quick notes.

Changing the selection and content of the sidebar is simple and elegant. To remove a panel, click the triangle in its heading and choose "Remove." To move a panel, pick it up by its heading and drag it elsewhere in the lineup. You can also download more panels at Google's site, although only five were available Friday.

In addition to providing a clever new interface, Google Desktop continues to be the best add-on search tool for Windows. It can now index data on external and networked drives and can scramble its own index against viruses. It also offers answers to a query as you type it, not after you hit the enter key.

And if you've grown weary of hunting down rarely used programs that dwell in the farther reaches of the start menu, you can just type their names into Google Desktop's search bar to run them.

While Google undercuts Microsoft in those ways, it gives the software giant a hand in another way: Google Desktop will add a search plug-in for Microsoft's Outlook e-mail program that can find old messages more quickly and easily than Outlook's built-in search tools.

Over almost three weeks of use, Google Desktop behaved well on all three test computers, sticking to a relatively small allocation of memory (at most, 25 megabytes or so). I haven't seen the program act like spyware in any way, nor have I read any such reports elsewhere. At worst, it's occasionally been slow to update its RSS feeds, and on one PC it didn't display any data after being briefly blocked by a firewall program.

Google is releasing the program as many other companies, such as Apple, Yahoo and Microsoft, are working on their own Web dashboards and sidebars. But Apple's Dashboard can't help Windows users and Yahoo's Konfabulator isn't tied into Yahoo's separate desktop-search program. Microsoft's sidebar won't appear until it ships Vista, the company's next operating system, sometime next fall.

For the moment, that leaves Google Desktop in a class by itself.

Living with technology, or trying to? E-mail Rob Pegoraro at rob@twp.com.