The new features will let users control their history, cookies and other information that IE8 stores. Other features aim to help users control how their browsing history is shared by Web sites. By default, IE8 browses the Web the same way IE7 does.

"Having privacy native in the browser as opposed to just an extension is something we've been advocating for a long time from all the browser manufacturers," said Ari Schwartz, deputy director at the Center for Democracy and Technology. "Incorporating all of these privacy features at once is a major step forward. Safari has some built-in privacy and Firefox has extensions. Native privacy is better."

Inside InPrivate Browsing

When a new feature called InPrivate Browsing is activated, new cookies are not stored. Rather, all new cookies become session cookies and existing cookies can still be read. New history entries will not be recorded and new temporary Internet files will be deleted after the private browsing window is closed. Form data , passwords, queries typed into a search box, visited links, and addresses typed into the address bar are not stored.

"If you are using a shared PC, a borrowed laptop from a friend, or a public PC, sometimes you don't want other people to know where you've been on the Web. Internet Explorer 8's InPrivate Browsing makes that 'over the shoulder' privacy easy by not storing history, cookies, temporary Internet files, or other data," Andy Zeigler, a program manager at Microsoft, wrote in the company's blog.

IE8 will also offer a feature to delete browsing history without deleting cookies that allow trusted Web sites to remember visitors. Financial Web sites, for example, often put a cookie on the PC to identify a user account to eliminate extra challenge questions that make logging in more tedious.

Blocking the Bad Guys

Another new feature, InPrivate Blocking, keeps a record of third-party items as users browse. When the privacy features are turned on, IE automatically blocks sites that have "seen" you across more than 10 sites. Since Web sites can track visitors without cookies, the only way to make sure data is not disclosed is to block the content and prevent communication to sites. InPrivate Subscriptions give users the ability to let software make the blocking decisions for them.

Microsoft's new efforts offer a good usability test for native privacy features in the browser, Schwartz said. In the future, however, the Center for Democracy and Technology would like to see the ability to leave the privacy features turned on all the time.

"Right now, each time you start a new browser session, you have to indicate that you want these features enabled," Schwartz said. "Second of all, all of these features are bundled together. So you can't just choose to block third parties but still keep your history. Being able to separate out those features will be useful to people in the future."