How to Move Firefox Tabs to the Left and Right Side of Screen

We've talked about how to move Firefox tabs from top to bottom, which in turn becomes my favorite tab position, especially after I discovered an extension that can add numbers to tabs (1 up to 8). Now, thanks to Jonathan who has let me know that there's an extension to move the tabs to the left side of the Firefox screen. It's called Vertigo.

Look at the screenshot below to see how your Firefox tab bar will look like.

Things to consider before you decide whether to install it or not:

Though the tab bar can be resized, you still have less screen width than the usual
You need to adjust the tab width to display all the close buttons of each tab. I set mine to 150. Less than that will make only the close button of active tab that is kept displayed.
If you install Tab Mix Plus extension, you will have to make some adjustments to run Vertigo's options properly as most of the options are overridden by some of Tab Mix Plus's settings.
Vertigo helps a lot when you often open many tabs as the vertically-positioned tab bar can display much more tabs than the horizontally one.
It works perfectly with Fancy Numbered Tabs extension as well.

Extra Tips:

Vertigo alone can only move the bar to the left. To be able to move it to the right, you need to install Tab Mix Plus, too. Here is how you can move the bar with Tab Mix Plus installed:

1. Open Tab Mix Plus Options located in Tools menu.
2. Go to Display section.
3. Select the Tab Bar tab.
4. Find the "Position" option and do the following: