Firefox 3 includes built-in warnings designed to protect you against those bad guys who want to trick you into giving up your credit card numbers, or download software infections to your PC. The browser throws up a warning when you try to visit a known crooked Web page. Take a look at how it works.

Interestingly, when I wrote "Review: Firefox 3 Burns Up The Web" just last week, the feature worked pretty badly. I tested Firefox against some obvious phishing e-mail and links to malware in my spam folder, and Firefox failed to trigger a warning most of the time.

But this week, when I tested Firefox again to make this video, it worked quite well -- Firefox set off the warning every time.

Did the protection improve that much in a week? Or were my tests bad? I'm looking into that.

For a look at another feature of Firefox 3, check out the previous video in the series: The Awesome AwesomeBar. Watch this space for two more installments.

Update 6/30: For another installment in our Firefox tour, check out our video on the browser's new ability to let you zoom Web pages.

Update 7/2: See the video on the new faster bookmarking system in Firefox.