Add-ons

Linkification by y5

Converts text links into genuine, clickable links...

Forecastfox Weather by Ensolis

Get international weather forecasts from AccuWeather.com and display them in any toolbar or statusbar with this highly customizable and unobtrusive extension.

Add-ons Manager Context Menu by Zulkarnain K.

Add more items to Add-ons Manager context menu.

Collector's Note This is scheduled to no longer work once XUL is deprecated (boo!). Hopefully someone can keep it working once/if that sad day happens.

Right Links by Infocatcher

This extension allows to open links in new tabs with right-click directly and using “long” left-click.
This is very useful for touchpads on notebooks and for mice without middle button.

AutoPager by Wind Li

AutoPager automatically loads next pages when you reach the end of a page. It works on a ton of sites,Google,Yahoo..
It works well with most other add-ons adblock plus, WOT and most of the greasemonkey scripts.
You can also try AutoPagerLite.

Collector's Note Extremely useful. Improves workflow tremendously.

Menu Editor II by Bogdan Butnaru

Hides or moves menus and menu items. (Deprecated version, see below.)

Copy Pure Text by Scatterplot

Allows to copy selected text as plain text by adding a 'Copy as Text' menu item to context menu.