Block a site that you suddenly came across and that you don’t want it to show up in the history, then HistoryBlock is one handy plugin to always have.It can block history entries, recently closed tab entries, download manager entries, cache entries and cookie entries.

TOCMonkey is a table of contents injection GreaseMonkey Script that can auto create Table Of Contents on webpages based on heading tags (h1, h2 and h3).The TOC can be seen on any webpages which did not earlier have a TOC sections.The position and TOC display can also be easily toggled.

Don’t mix you to be reviewed pages with bookmarks use Read it Later a firefox plugin lets you save pages of interest to read later directly from the address bar and all saved pages can be organized and saved offline for later reading.It also supports other browsers and has mobile apps aswell

Locate and Backup your Firefox Profile [Firefox 3.6] manually for easy restoration of firefox profiles after fresh installation of Firefox.Information on your installed Firefox Extensions, Enabled plug-ins with their versions and ID and the preferences set in Firefox can also be viewed.

Improve the boring blank Firefox new tab with easy to use information like most viewed sites, to do notes app, launch desktop app, open recently closed tabs, browse bookmarks and with 7 themes to choose from using New Tab King – Firefox Addon

NiceTranslator is a online language translator powered by Google and which can instantly translate your text into multiple languages at once.This online translator supports 50+ languages.The translated text can be copied and pasted anywhere as well.

FireFix is a Firefox Addon that learns from your typos and suggests you addresses by watching which page you go to after a DNS typo.The addon is activated only when the page is not found.

Use Google URL Shortener Service without installing the Google Toolbar in any browser using the Bookmarklet or the Firefox Goo.gl Lite Addon.