If you use Firefox as your primary browser, you probably get stymied occasionally by websites that don't look right in its windows. Don't fire up Internet Explorer (IE), which maintains a separate history and won't have your bookmarks; instead, use the IE Tab plug-in to instruct Firefox to temporarily use IE's rendering engine. IE Tab sits in the bottom-right corner of your browser. Click the Firefox icon to switch to IE mode and vice versa.
Want a copy of the current window you're visiting, complete with the history of that browsing session?
IE users can accomplish this without having to install and use a plug-in: press Ctrl, N to open a new window that shows the entire history of the current window.
For Firefox users, Duplicate Tab lets you obtain such a history with a single shortcut keystroke, or you can use the tool to merge multiple open windows into a series of tabs.
The standard 'Server not found' page is no help if you're looking for a website that's gone missing. ErrorZilla adds a series of buttons to the bottom of the standard Firefox message, providing instant access to the Wayback machine, Google Cache and more.
Internet Explorer users can obtain search-as-you-type functionality that works the same way it does in Firefox with this simple extension.
The Extended Statusbar plug-in supplements the data that Firefox provides about a web page and your internet connection, providing such details as the total size (in KB) of the page, the transfer speed and the load time.