This extension adds a menu button next to the address bar with actions
relevant to the current URL. The button's menu allows you navigate up
through the current URL's parents, to visit the equivalent ftp URL, or
to visit the site in archive.org. A single click on the menu button
also easily clears the location bar (much like the one in Konqueror) -
useful for keyboard free browsing.

It also has a few security control tick-boxes (popups, tabbing,
images) and the ability to add custom URL conversions/manipulations.

WWW: https://addons.mozilla.org/en-US/firefox/addon/3763