Web browsers take entirely too much room on the screen. I've seen tips for putting Firefox on a diet, but nothing that frees up as much space as my bag-o-tricks.
So let's go.
First, go to View, Toolbars, and Customize. Drag the address bar and search bar up to the top, next to the File/Edit/View/History/Bookmarks menus. Drag the arrows up there too, if you want them. Click OK. Now to back to View, Toolbars, and uncheck the navigation and bookmarks toolbars.
Now do a Google search for "classic compact Firefox theme." Install it.
You'll have significantly more screen real estate.