How private -- or secure -- is private browsing?

All the major browsers--Firefox, Internet Explorer 8, Safari, and even --now have or will soon have a major privacy feature. The name varies from browser to browser, but the basic intent is largely the same: While active, it masks your browsing trail from anyone who might later sit down at that PC and try to check the browser's history, cookies, and other data.

While these features should prove effective in that situation, they won't disguise you from the sites you visit; sites will still be able to record your IP address and monitor the searches and other information you enter. And more important, the technology won't make you any more or less safe from when you view a page--the favored approach among money-minded digital crooks these days. So you'll still need to be careful where you surf.

Safari's Private Browsing feature comes with its ; for to use its InPrivate option. The feature is called Incognito in the release. Firefox is set to add its Private Browsing to the upcoming 3.1 release, but at press time .

In general the functions work (or will work) in a similar fashion. You start by telling the browser to initiate a private browsing session, which for IE 8 and Chrome means you'll get a new window with clear visual indicators that you're in a private session. Safari, unfortunately, uses the same browser window with no visual cues (after an initial pop-up confirmation), so you might easily forget you're in private mode--or think you're in the mode when you aren't. Mozilla isn't saying whether it plans to use a separate window or other visual indicator for its feature.

In private mode, the sites you visit won't be added to the browser's history. When you leave the mode, the browser deletes any cookies added during the session, and clears the download list (or, in the case of Safari, the list won't acquire new entries in the first place). However, downloaded files will stick around unless you manually delete them, as will bookmarks you add yourself.

Secrecy--Not Security