Render a site in Internet Explorer every time when using Firefox

As a Firefox user, there are a few times that I run across a site that requires Internet Explorer (IE). With the right add-ons to Firefox, it's easy to switch the rendering engine with a single click. Of course it would be even easier if the site Firefox recognized sites that require IE, and switch for me. If you use the IE Tab add-on, that is exactly what you can configure it to do. Here's how to do it:

1. Download and install the IE Tab add-on (like all add-ons, this will require a restart of Firefox)
   
2. Go to the site that you want to render each time in IE
3. Open the IE Tab Options (Tools >> IE Tab Options -- Sites Filter tab)
4. The page you just navigated to should be in the URL box, so you just need to click Add
   You can skip step 2 and enter any URL manually into the URL box
5. Click OK

Now every time you go to a site that is listed in the Sites Filter section of IE Tab, it will automatically render in Internet Explorer.
There's one more trick related to this that may be required for some sites. Sites will typically look at the User Agent of a web browser -- this tells the site what browser you are using -- to determine how certain aspects should render or even whether it will display a page. Use the add-on, User Agent Switcher, you can tell a website that you have a browser that is different than the one you are actually using.
The particular site I use IE Tab with will not even let me login if the User Agent doesn't indicate Internet Explorer. So in addition to adding IE Tab to my browser, I had to add User Agent Switcher. Now any site I visit, by default it thinks my browser is Internet Explorer, even though it is really Firefox.