Note: If you are using the latest version of Firefox, please use the new extension MileWideBack-WebExt.
Navigate back by clicking on the left border of the window, right-click to go forward, middle-click to close tab, wheel for next tab.
The left edge of your browser window becomes a multi-purpose button. It is infinitely wide because your mouse can continue to travel left, while the cursor will remain stuck to the edge of the screen.
For optimal usability, please make sure that your window in maximized.
The trick is to fling your wrist to the left. No accuracy or coordination is needed here. You could even do this blind-folded.
Then proceed to left/middle/right click the mouse as desired or rotate your mouse wheel.
* Left click to navigate back
* Right click to navigate forward
* Middle-click to close the current tab
* Rotate the mouse wheel to cycle through your open tabs