Among the many reasons why Firefox is superior to Internet Explorer is its use of extensions, add-ins that give it all kinds of cool new features.

Wei-Meng Lee tells you how to use extensions and picks some of his favorites in his article Using Extensions in Firefox. But there are more great extensions than can be fit in a single article, and so I thought I’d tell you about some of my favorites as well.

If, like me, you hate having to register at Web sites before you can do something as simple as read an article, then you should get BugMeNot. When you get to a page that requires a user name and password, right-click on the page, and the extension will give you a pair you can use.

One of the slimier and increasingly popular scams on the Internet are phishing attacks, in which a site looks like real ecommerce site like PayPal or CitiBank, but in fact is a forgery, including what appears to be the real URL in the address bar. Type in your name and password, and a scammer has access to your account. The great SpoofStick extension fixes the problem by showing you the true URL you’re visiting, no matter what the address bar says.

Like it or not, some sites are built specifically for Internet Explorer - they don’t display properly in Firefox. So get the ieview extension and when you come to a page like that, right-click and choose View This Page in IE, and Internet Explorer launches, with the page displayed.

Single Window helps you get the most out of tabs. When a page launches that would normally launch in a new browser window, the extension instead puts it on a new tab. And Close Tab on Double Click does exactly what it says - it lets you close any tab by double-clicking it.

There are a lot more great extensions you should check out as well. Get them here .

What are your favorite Firefox extensions? Let me know.