User:Jacobbrett/Let Address History act like BASH's Command History
From MozillaWiki
A rather simple request: add an option in Firefox's preferences to activate a "Command History" mode that would scroll through previously entered addresses when the user is editing the address in the address bar.
The address history could be scrolled through by pressing the 'up' and 'down' arrow keys, or, perhaps 'Ctrl'+'Shift'+'Up arrow' and 'Ctrl'+'Shift'+'Down arrow', as to not interfere with the "Awesome Bar" feature). The address bar's text would change to reflect each up/down press.
See a command-line program (e.g.BASH) for an example of this implementation.