Add-ons

DownThemAll! by Nils Maier, Federico Parodi, others

The first and only download manager/accelerator built inside Firefox!

Collector's Note Superb download manager. Allows downloads to resume after interruptions. Also speeds downloads.

Session Manager by Michael Kraft

Session Manager saves and restores the state of all or some windows - either when you want it or automatically at startup and after crashes. It can also automatically save the state of open windows individually.

Collector's Note Save and restore sessions automatically.

Disable Add-on Compatibility Checks by Kris Maglione

Reinstates the extensions.checkCompatibility preference without respect to the current application version.

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 Endless loading pages.

Email This! by ArtSabintsev/Lazyrussian

Email This! will send your recipient the link, title, & highlighted text of the page you are viewing using GMail, Google Apps GMail, Yahoo, and Stand-Alone Mail Clients like Outlook Express, Thunderbird, & More!