HistoryBlock is a Firefox add-on that works like Google Chrome's Incognito mode or Internet Explorer 8 / Firefox 3.5 Private browsing mode but with a difference. You don't need to switch between the modes, instead HistoryBlock automatically clear your browsing history of a website that you specified.

After installing the add-on, click the "Options" button under the add-on and add a hostname to be blocked (example ebay.com, yahoo.com, google.com etc.). It will clear your surfing data from the history tab, cookies, the recently closed tabs list, and the download manager list.

Alternatively, now you can simply right-click on a page that you visit and hit "Block This!" from the context menu. It will automatically add the hostname and/or sub-domain of the current page to the blacklist.

Install HistoryBlock from Mozilla’s add-on site.