Nav Bar Height (an add-on for Firefox in Windows, Linux, OS X)

Download, details and screenshots at https://addons.mozilla.org/en-US/firefox/addon/nav-bar-height/

Description

This add-on adds a context menu option to change Navigation Bar height in Firefox. Available sizes are 24px, 26px, 28px, 30px, 32px, 34px, 38px, 40px (the default height).